The effects of circumferential total pressure distortion and different types of swirl distortion on the performance and stability of three-stage transonic fan are studied by the body force model （BFM） and computational fluid dynamics （CFD）， and the characteristics of distortion transfer and flow field inside the fan are investigated. The results show that the calculated results of BFM and CFD agree well. The maximum error of BFM and CFD calculation characteristics under uniform air intake is less than 4%. The 120° circumferential total pressure distortion degrades the performance of the fan， and the stable boundary moves downward. During the axial process， the overall intensity of total pressure distortion decreases， while the overall intensity of total temperature distortion increases. The distortion of the co swirl decreases the fan pressure ratio and delays the stall， while the cou swirl distortion has the opposite effect on the fan. Due to the dominant role of the co swirl in the twin swirl flow， the fan pressure ratio characteristics are lower than the uniform intake and the distortion of the cou swirl flow， and the change of the characteristic line is similar to the distortion of the co swirl flow. The distortion of twin swirl induces total pressure and total temperature distortion， and then through attenuation at all levels， the distortion intensity shows a decreasing trend.