For manufacturing small batch of thin wall polyphenylene sulfide (PPS) parts, the method of viscous medium warm bulging to form PPS sheet was proposed, and the viscous  medium warm bulging process was researched. Then, the engineering stressstrain curves and the section shrinkage rates of PPS sheet at different temperatures and different tensile speeds were obtained by the uniaxial tensile tests, and the influences of forming temperature and viscous  medium medium loading speed on the center section profile and wall thickness distribution of PPS sheet bulging specimens were obtained by the method of viscous warm bulging tests. The research result shows that when the temperature ranges from 100 ℃ to 180 ℃, the formability of PPS sheet is enhanced with the increasing of temperature and decreasing of loading speed. Thus, under the certain loading speed and temperature condition, small batch of thin wall polyphenylene sulfide (PPS) parts can be formed by viscous  medium warm bulging process.