In order to improve the sealing performance of the labyrinth seal between the compressor stages,four types of bushing structures,namely rectangular slotted,trapezoidal slotted,rectangular retaining ring and trapezoidal retaining ring,were designed.Influences of the bushing structures on leakage characteristics under different pressure ratio and clearances were studied,and their characteristics were compared with those of smooth bushings.The results show that with the increase of the pressure ratio,the flow speed of the fluid increases,which leads to an increase in the leakage of the seal.However,setting a baffle ring on the bushing can directly block the flow of the wall jet,and the trapezoidal baffle ring can guide the jet to flow back,which aggravates the complexity of turbulence in the tooth cavity,so the growth rate of leakage gradually slows down.Under the same clearance,the sealing performance of the retaining ring bushing is the best,and the grooved bushing has a better sealing advantage only under a certain clearance value,but the sealing advantage of the retaining ring bushing is gradually enlarged with the increase of the clearance.Therefore,the sealing performance of the retaining ring bushing is better under the condition of high pressure ratio and large clearance,and the trapezoidal retaining ring has more advantages.