The flow field grid model of compressor for a smallsized vehicle turbocharger was established by using Numeca numerical software, the effects of different blade tip clearances on the compressor performance were then studied and it was found that the blade tip clearance had great influence on compressor performance. An increase of 0.1 mm in the tip clearance led to the reduction of pressure ratio by about 3% and efficiency by about 2%. The abradable coating was developed for the blade tip clearance of compressor, which reduced the actual clearance between the blade and volute. After using the abradable coating, the test peak efficiency of compressor  increased by nearly 1.5% and the pressure ratio of each speed also improved. The coating was worn evenly after a long period of operation at high speed and the compressor impeller still kept well enough after contacting with the coating. The hightemperature abradable coating was further developed for the turbine end. The comparison of engine matching test results showed that the low and middle speed torque increased by about 2% and the specific fuel consumption reduced by 3.5% at 1 883 r/min. The 200 h endurance test of turbine shell coating was carried out and it was found that the coating was worn evenly without spalling and the turbine blade is still intact after contacting with the coating, which verified that the abradable coating was feasible in the application of vehicle smallsized turbocharger.