Boundary layer ingesting technology (BLI) has been widely developed, but the relevant research on the rear engine concept (REC) still needs to be expanded, especially for the different characteristics of the total pressure distortion and the swirl distortion. The paper investigates the BLI inlet distortion of a REC aircraft and its effect on the fan performance by commercial software CFX. Numerical simulation is conducted to obtain the inlet distortions first and the impact of these distortions on the characteristics of NASA rotor 67 is evaluated. Results show that the distortion tends to increase with the increase of the fluid redistribution effect of the fuselage-propulsor fusion part. Comparatively, the inlet distortion caused by AOS has a more significant influence on the performance of the fan. The swirl distortion is concentrated in the edge region of AIP. The total pressure distortion which coupled higher level of swirl has a more significant effect and is offset in the circumferential direction with the continuation effect of distortion in other leaf channels not obvious.