He was the founder of differential geometry in China, and served as president of Fudan University and honorary chairman of the Chinese Mathematical Society.
Su successfully passed the entrance examination for Tokyo Higher Technical College in February 1920 and enrolled in the Department of Electrical Engineering where he graduated from in March 1924.
Under the supervision of Tadahiko Kubota, Su received his Ph.D. from the university in 1931 for dissertation entitled The relation between affine and projective differential geometry.
After returning to China, he first served as a professor and dean at Zhejiang University (he established the Chen-Su School with Chen Jiangong).
In 1985, the Propaganda Department of the Zhejiang Provincial Party Committee appointed Su as the honorary President of Wenzhou University.
Some other positions Su held included member of the sixth (1983–88) and later vice chairman of the seventh and eighth (1988–98) National Committee of the Chinese People's Political Consultative Conference (CPPCC), honorary chairman of the China Democratic League Central Committee (1997), and Conference and deputy to the National People's Congress (NPC).
Su won the second prize of the first National Science and Technology Progress Award in 1985 for his collaborative effort on "A Production Process of the Hull Form by the Curved-Surface Method."