Author: Zhang Shu (Professor at the School of Education Sciences, Sichuan Normal University) and Zhu Yan (PhD student at the School of Education Sciences, Sichuan Normal University) Teachers are the primary resources for educational reform, and the construction of the teaching staff is an important part of the strategy of building a strong education country. Improving the quality of the teaching staff comprehensively and leading the professional growth of teachers is an inevitable requirement for comprehensively deepening education reform. How to reduce the burden on teachers and ensure that they fully invest in teaching and educating people is an important issue related to the healthy development of education and the stable optimization of the teaching staff. Currently, with the deepening of informatization and digitization, the requirements of social production for the quality of workers are constantly improving, and there are also newer and higher requirements for the ability and literacy of teachers. The role of teachers has gone beyond the traditional positioning of educators and become more diverse and three-dimensional. In the process of teacher role evolution, many problems such as blurred boundaries, alienation of responsibilities, and functional overload have emerged, significantly affecting the physical and mental health and professional development of teachers. The heavy burden on teachers is mainly manifested in two dimensions: the blurry boundaries of the teacher's role and the overload of tasks. Fuzzy boundaries refer to the arbitrary expansion and extension of teachers' power and responsibility boundaries, extending their work space from schools to various fields such as families, communities, and society, and taking on more and more tasks beyond their roles. Due to the high ethical expectations of traditional culture towards the role of teachers, as well as the diverse demands of management departments, parents, and even various sectors of society for education, teachers have to undertake social affairs unrelated to teaching, such as traffic safety, community services, borrowing, and writing materials, in addition to teaching. The overlapping responsibilities and obligations of multiple social roles have caused teachers to drift between "education professionals" and "social affairs assistants", gradually deviating from their professional duties of "teaching and educating people". Overloading refers to the continuous increase in tasks within the teacher's role, resulting in excessive competition, high expectations, and meticulous management, resulting in workload exceeding the normal range and being in an overloaded state of operation. Faced with the expectations of parents, the requirements of the education administration department, and the performance evaluation of schools, teachers are trapped in various "internal disputes" and have been in a state of tension and pressure for a long time. High intensity work causes teachers to lack energy and autonomy, which directly restricts their professional experience and development. In the author's opinion, educational and teaching tasks with appropriate levels are inherent in the existence of teachers. Therefore, how to define the burden of teachers has become a prerequisite for problem-solving. If the reasonable limit and boundary line of teachers' burden can be scientifically and effectively determined, it can not only regulate and constrain teachers' educational and teaching behavior to a certain extent, but also measure whether to reduce teachers' burden and how to reasonably reduce it. The author believes that the basis of judgment lies in clarifying the teacher's professional role - teaching and educating people, and based on this, formulating evaluation standards to scientifically measure and dynamically monitor the teacher's burden. Due to the highly individual subjectivity of burden perception, different teachers may have vastly different perceptions of burden even when facing the same work task. Therefore, it is necessary to comprehensively consider subjective and objective factors in the judgment criteria of burden rationality to ensure the effectiveness and scientificity of the results. Objective factors include physical characteristics such as the nature, time, and volume of the work task; Subjectively, it involves the teacher's perception and emotions