To better grasp these two overall situations, we need to use the system concept, consider them from the perspective of the overall situation, grasp the regularity and interaction of the two overall situations, and enhance the consciousness and initiative of coordinating the two overall situations. Engels pointed out: "the theoretical thinking of each era, including the theoretical thinking of our era, is a product of history. It has completely different forms and contents in different times." System concept is an important philosophical thinking and theoretical thinking. It is a basic thought and working method. The concept of system is based on dialectical materialism and the development of modern science. It not only embodies the views of materialist dialectics on connection, integrity and development, but also embodies the concepts of system theory on structure, function, elements and openness. Adhere to the concept of system, emphasize the inherent connection of objective things, and treat the cognitive object as a systematic, organic, developing and open whole. To coordinate the overall strategic situation of the great rejuvenation of the Chinese nation and the great changes in the world that have not occurred in a century with a systematic concept, we need to deeply understand the new characteristics and requirements brought about by the changes of the main social contradictions in China, deeply understand the new contradictions and challenges brought about by the complex international environment, unify planning with planning for the situation, the present and the future, and constantly enhance the systematicness, predictability and creativity of our work. Using the concept of system to coordinate the two overall situations requires insight into time and potential. "Time" is a new opportunity and new characteristics of the times, "potential" is the development trend or trend. Entering the new era, we should accurately grasp the new historical orientation, new changes of the times and new requirements of practice of socialism with Chinese characteristics. Establish a correct view of history, the overall situation and the role, grasp the historical law, understand the historical trend and lead the historical trend from the height of the combination of historical logic, practical logic and theoretical logic. On the one hand, we should base ourselves on the great historical cause of the great rejuvenation of the Chinese nation, comply with the great leap of the Chinese nation from standing up, becoming rich to becoming strong, and write a magnificent chapter of the new era; We should also deeply grasp the dialectical relationship between the overall strategic situation of the great rejuvenation of the Chinese nation and the great changes in the world that have not been seen in a century, base ourselves on the overall situation, coordinate the overall situation, lead the changes, create a new situation, strive to achieve progress, breakthrough and win in the changes, maintain strategic concentration in the changing international situation and move forward towards the set goals. Using the system concept to coordinate the two overall situations needs to closely link the history of the Chinese nation with the history of the world. The overall strategic situation of the great rejuvenation of the Chinese nation is an important variable of the world's unprecedented great change in a century. Fully promoting this strategic situation can effectively promote the evolution of the world's unprecedented great change in a century in a direction conducive to the construction of a community with a shared future for mankind. The great changes that have not occurred in the world in a century are the macro environment of the overall strategic situation of the great rejuvenation of the Chinese nation. A clear understanding of the important period of strategic opportunities for China's development, making good use of the "five strategic advantages" and taking the "five only ways" can continue to create new and greater miracles in the new era and journey. Using the system concept to coordinate the two overall situations needs to deal with the relationship between China and the world. The development of the world needs China, and China's development is inseparable from the world. At present, the century changing situation and the century epidemic situation are intertwined, and the world has entered a new period of turbulence and change. The challenges facing the world are more overall, complex and uncertain. At the same time, we should see that countries are increasingly interconnected and interdependent, the balance of international power is becoming more balanced, emerging market countries and developing countries are increasing their own strength, independent development capacity and international influence, and the general trend of peaceful development is irreversible. We should always stand on the right side of history and on the side of human progress, hold high the banner of peace, development, cooperation and win-win results, carry forward the common values of all mankind of peace, development, fairness, justice, democracy and freedom, promote the construction of a new type of international relations, promote the construction of a community with a shared future for mankind, lead the trend of human progress, and provide Chinese wisdom and Chinese solutions for the development of world civilization and the settlement of human problems. Using the system concept to coordinate the two overall situations requires mobilizing all positive factors, uniting all forces that can be united at home and abroad, straightening out various relations, preventing various risks, and constantly promoting the great cause of socialism with Chinese characteristics in the new era. We should properly handle the relationship between the "overall situation" and the "chess pieces", both strategically and strategically. The world has entered a new period of turbulence and change. The task of domestic reform, development and stability is heavy, and risks and challenges come from time to time. There are many problems to be solved. In the face of many contradictions, we must keep a clear head, distinguish between primary and secondary contradictions, and grasp the complex relationship of various contradictions from the overall situation. Firmly grasp the key links that affect the whole body, plan and serve the whole situation from the overall situation, constantly improve the integrity and synergy of all work, promote deeper reform and higher-level opening-up, constantly enhance the confidence and determination to realize the great rejuvenation of the Chinese nation, and enhance the determination and confidence to effectively deal with the great changes in the world that have not been seen in a century. (Xinhua News Agency)