Aiming at the problem of sealing performance of the rotary combination,a device that can perform a seal performance test on a rotating combined seal for shafts with a diameter of 100 mm was designed.The device adopts PLC control drive to realize system data collection and pressure and speed automatic adjustment control,which can test the torque and leakage of seals under different speeds and pressures.This test device was used to conduct experimental research on a certain type of rotary combination seal.The results show that at constant speed,the starting friction torque of the combined seal is increased with the increasing of the pressure.Under the same pressure,the friction torque of the combination seal ring is increased with the increasing of the rotating speed at low speed.When the speed increases to a certain value,the increase of the friction torque shows a downward trend.The test results also show that the device has perfect functions,easy operation,small selfrotation resistance,and stable and reliable operation under high pressure.