A native of the Qi'ao Island of Xiangshan County, Guangdong Province, he became a sailor, active in Sun Yatsen's nationalist organization Tongmenghui, and took part in organizing the Sailors' Union in 1920.
Su participated in formulating the plan for the Guangzhou Uprising in 1927, and was elected President of Peasants' and Workers' Democratic Government of Guangzhou. Simultaneously, he acted as Minister of Labour in the Leftwing KMT Government of Wuhan.