In order to capture the rear stages’ clearance effects of high pressure compressor with tandem stator, a redesign of a high-turning tandem cascade was studied in the manner of linear cascade with different clearance sizes. The cascade performances, tip loading and the development trajectory of leakage vortex were compared with collateral inlet boundary layer and skewed inlet boundary layer. The results show that the tip region blockage is burdened and total pressure loss is sharpened with the clearance increasing. With the skewed inlet boundary layer, the pressure loss is decreased to some extent, and with small clearance the blockage of low span is relieved dramatically. Two leakage vortexes are captured near the tip region with 2% span clearance, and the front blade’s leakage vortex will vanish in the passage. The effect of skewed inlet boundary layer prolongs the trajectory of front blade leakage vortex. With the clearance increasing, the roll-up point moves downstream.