Abstract: In order to study the performance of oil seal under medium-low pressure conditions, TC, TCG, TCV and TCGZ oil seals for oil pump were chosen for experiment. The friction torque and temperature of the matching shaft end face which near sealing area under different pressure and different speed were tested by self-built experimental platform. During the experiment, the shaft speed was within 600~8 000 r/min, the pressure of sealed YH-15 aviation hydraulic oil was within the range of 0~0.2 MPa. The results show that the relationship between friction torque and speed was strongly dependent on oil seal’s structure and oil pressure. The friction torque and shaft end temperature of TC were sensitive to the change of oil pressure, TC’s performance under medium-low pressure conditions was not good. Because of short and thick lip, oil pressure had limited effect on TCV’s performance, that is to say the pressure resistance of TCV was good. The effect of oil pressure on the friction torque of TCG and the average temperature of the shaft end face was the most obvious, TCG was not suitable for sealing medium under medium-low pressure. Compared to TCG, the influence of oil pressure on the tribological properties and temperature of TCGZ was not pronounced. However, compared with TCV, its pressure-resistance performance was lower.