Based on the self-circulating sand blasting and suction equipment, the self-circulating sand blasting technology test platform is built. The technology parameters of mild sand blasting are studied, and the steel plate surface characteristics under different sand blasting pressure and sand blasting speed are explored. The results show that the steel plate surface roughness increases gradually with the increase of sand blasting pressure and decreases gradually with the increase of sand blasting speed. The research method and results can provide reference for the implementation of secondary surface treatment of ship sections.