Recently, the reporter visited the Jinping Underground Laboratory in China, which is located in the middle of the Jinping Mountain Tunnel in Liangshan, Sichuan Province. The laboratory is the largest underground laboratory in the world. The 2400 meter rock depth blocks a large amount of radiation from the mountain. The high-purity germanium detector in the laboratory has six layers of "armor", including polyethylene, lead and copper, shielding neutron, gamma ray and other radiation sources layer by layer. If the recoil energy left by the detector's material in the "mountain crossing" collision is different from that of ordinary matter, it may be dark matter, which is "waiting for the hare". (The picture shows Jing Mingkun, scientific research assistant of China Jinping Underground Laboratory, introducing the appearance of the laboratory on October 26.) (The picture shows Nie Qiyuan, a doctoral student in the Department of Engineering Physics of Tsinghua University, monitoring the experiment on October 26.) (The picture shows Jing Mingkun, scientific research assistant of China Jinping Underground Laboratory, selecting radiation testing materials on October 26.) (The picture shows Nie Qiyuan, a doctoral student in the Department of Engineering Physics of Tsinghua University, maintaining the experimental equipment on October 26.) (The picture shows Jing Mingkun (right), the scientific research assistant of China Jinping Underground Laboratory, and Nie Qiyuan, the "post-95" doctoral student in the Department of Engineering Physics of Tsinghua University, discussing their work on October 26.) (The picture shows Jing Mingkun, scientific research assistant of China Jinping Underground Laboratory, injecting liquid nitrogen into a container on October 26.) (The picture shows the tunnel entrance of China Jinping Underground Laboratory on October 26.) (Liu Xinshe)