To explore and improve the leakage properties of the hydro-viscous clutch rotating seals,the sealing performance test was carried out through the Tr1-6Kr-22A variable speed test bench,and the effect of operating parameters and structural parameters on the leakage of each channel was compared and analyzed. The results show that the overall leakage of the control oil is relatively large, and the lubrication oil leakage channel is least affected by pressure.As the pressure of the control oil increases,the leakage of each leakage channel also increases.The influence of oil pressure on the sealing leakage amount is more obvious than that of the speed,and the leakage amount increases smoothly under high pressure conditions.The width of the sealing ring has a significant impact on the leakage rate.A wider sealing ring can effectively reduce the overall leakage rate of the seal.The test fixture with wider seal ring has the smallest leakage in each channel and is less affected by operating parameters,making it suitable for situations with large pressure fluctuations.However,when the speed fluctuation is large,the sealing leakage exhibits a step characteristic.