IIn order to develop a hollow fiber ultrafiltration membrane with low cost and excellent performance, CPVC/SPSF blend hollow fiber ultrafiltration membrane was prepared by solution immersion precipitation phase conversion process using cheap chlorinated polyvinyl chloride (CPVC) as film forming polymer and sulfonated polysulfone (SPSF) as hydrophilic modification additive. The effects of SPSF mass fraction on the structure and properties of CPVC/SPSF blended hollow fiber ultrafiltration membrane were investigated based on the characterization and testing of FTIR, SEM, DSC, DTG and contact Angle, as well as the determination of porosity, pure water flux and BSA retention. The results show that the mixing enthalpy (ΔHm) of the CPVC/SPSF blending system is less than the critical value (4.168×10-2 J/mol), and the CPVC/SPSF blending system is fully compatible. With the increase of SPSF mass fraction from 0 to 1.20%, the porosity of CPVC/SPSF blended hollow fiber ultrafiltration membrane increased from 15.20% to 22.50%. Water contact Angle decreased from 102.20° to 80.60 °. The pure water flux increased from 65.30 L/(m2·h) to 182.10 L/(m2·h), and the BSA interception rate decreased from 95.78% to 88.17%. When the mass fraction of SPSF was 0.60%, the breaking strength and breaking elongation of CPVC/SPSF blended hollow fiber ultrafiltration membrane were the maximum values, which were 0.1585 cN/dtex and 26.4%, respectively.