Several ten-stages-compressor of a high bypass ratio turbofan engine was used as the research object, the change law of tip clearance and its effects on aerodynamic performance and stable boundary of the compressor were investigated based on a high speed compressor component, core engine and complete engine test facility. The mechanism and the sensitive area of tip clearance effect on the overall performance and each stage performance of multistage compressors was revealed by detailed simulation results of transonic and subsonic stage performance. The results show that the clearance change law of compressors of different sizes is consistent, which is mainly related to centrifugal force and temperature filed. Flow-pressure ratio and flow-efficiency characteristics of the compressor at design rotational speed Indicate a feature of whole reduction while the clearance increases, and the clearance has more impact on the back subsonic stage. With the increase of the tip clearance, the efficiency of the front transonic stages of the compressor does not decrease for the small ratio of clearance to the big blade height, but the work capacity of the back subsonic stage decreases obviously, and the influence of the clearance mainly concentrates on the back subsonic stage, which makes the compressor efficiency and stall margin droop.