The preparation and performance characterization of polymer ultrafiltration membranes were studied in detail by polysulfone material and phase conversion method. In order to control its microporous structure, the membrane production conditions were systematically studied, including the selection of polymers, solvents and additives. The film-forming process conditions were optimized by orthogonal experiments. The results showed that the concentration of polysulfone in the casting solution had the most significant effect on the water flux of ultrafiltration membrane, followed by acetone content, solvent evaporation time, and polyvinylpyrrolidone content. On this basis, the preparation conditions of polysulfone base membrane were optimized: the mass fraction of polysulfone was 14%, the solvent evaporation time was 10 s, the mass fraction of acetone was 0.3%, and the mass fraction of polyvinylpyrrolidone was 0.25%.