Abstract: To discuss the human operating ergonomics at different pressure level for the capstan partial pressure suit (PPS),range of motion (ROM), operational flexibility, grip strength test and subjective survey were performed by ten male subjects while wearing PPS under 6 pressures. The control group was under 0kPa. The results show that: ①The PPS pressures have significant impacts on operating ergonomics (P<0.05). Shoulder joint and hip joint are more sensitive to the pressure and decrease 62.2% and 42.3% respectively under 1.96 kPa. Under 10.49 kPa, two indexes of ROM decrease the most: shoulder extension by 83.1%, and neck rotation by 63.3%; ②Upper lamb is affected more severely by pressure than the lower lamb; ③The pressure has no significant influence in grip strength test (P>0.05); ④The consistence of subjective test results and the objective data reflects the human body compensatory response to different pressures. The results provide basic data for ergonomic evaluation and can be practically applied for improving the performance of PPS.