To investigate the influence of a non-parallel rotor blade tip clearance structure on a compressor, this paper studies the effects of different rotor blade tip clearance values on compressor performance and flow field structure and identifies the optimal clearance value. Based on the design clearance value and the optimal clearance value, three expansion clearance distribution schemes were proposed to analyze their effects on compressor performance and flow field structure. The research results indicate that when the rotor tip clearance is set to 0.5τ, the stability margin improvement of the compressor is relatively large, and the performance of the compressor is superior near the stall point. The flow field structure near the stall point is relatively good, and 0.5τ clearance (P2) is considered the optimal clearance value. If the parallel gap distribution is changed to the expansion gap distribution D1, D2 and D3 schemes, the low-energy fluid vortex near the rotor pressure surface is significantly weakened. For the low-speed zone near the trailing edge of the blades, it is further blown away, improving the flow structure and increasing the stall margin. Compared with the baseline scheme, the D1, D2 and D3 schemes improve the stall margin by 1.6%, 1.9% and 2.4%, respectively. The total pressure ratio and efficiency stability margins are improved by 3.18%, 8.56% and 6.20%, respectively. The stability margin improvement rate is increased by 0.59%, 1.45% and 1.55%, respectively. The results provide insights into optimizing the clearance distribution structure for axial flow compressors.