In order to analyze the distortion effects of the skewed PC box-section girder bridge, a simply-supported and three-span continuous skewed PC box-section girder bridge models are built by using the finite element analysis software ANSYS in this paper. First of all, the distortion effects in the longitudinal direction are analyzed for the bridge models and the most disadvantage section are found. Then the longitudinal distortion effects how to vary with the slope is discussed. The results show that the influence of slope is remarkable, with the increase of slope, distortion is becoming more and more large, and it is proportional to the slope degree, the distortion angle of 1/4 span and 3/4 cross section of the bridge is the largest. Therefore, in the process of design, construction and maintenance, the deformation of unfavorable cross section should be paid special attention.