During the 25 years from the establishment of 1927 Department of Mathematical Sciences in Tsinghua University to the adjustment of 1952 Department, famous mathematicians such as Zheng, Xiong Qinglai, Zhao Fangxiong and Duan Xuefu successively served as the department heads in Tsinghua. They not only actively introduced and adopted the most advanced mathematics teaching system in the world at that time, but also advocated academic research and recruited talents. In just 25 years, Tsinghua's mathematics has gone from creation to glory. During this period, Sun Guangyuan, Zeng, Hu Kunsheng, Xu, Hua, Zhuang Qitai, Min Sihe, Cheng Minde, Wu Xinmou, Wan Zhexian, Feng Kang and other famous domestic mathematicians came to Tsinghua to teach. 1935 also invited J.Hadamard, a French mathematician and then vice chairman of the World Computing Society, and N.Wiener, an American mathematician and founder of modern cybernetics, as visiting professors. During this period, a number of mathematical talents emerged, such as Hua, Wu Daren, Zhuang Qitai, Xu and Zhao Ke. It can be said that internationally renowned mathematicians, such as Hua, went to the world from the Department of Mathematics of Tsinghua University, and their brilliant achievements had a far-reaching impact on the development of contemporary mathematics. Because of advocating equal emphasis on teaching and research, a number of influential research results were achieved at that time. For example, the theory of infinite meromorphic functions established by Xiong Qinglai in meromorphic functions; Yang Wuzhi's pioneering work in the study of modern number theory in China, The Hualin Problem of Pyramid Number; Hua's research on prime number transformation and Waring problem of variable prime number equation in analytic number theory: Chen Shengshen's research on Gaussian-wave formula in differential geometry, topology and Finsler geometry, etc. 194 1 year, Hua's theory of piling up prime numbers won the first national academic research and book invention prize awarded by the Ministry of Education, and Xu's paper on Mathematical Statistics won the second prize.