Based on the aberration theory of plane symmetric optical systems, the expressions of each type of wave aberration of fisheye lens were formulated. The autocorrelation integral was used to calculate the modulation transfer function of the fisheye lens. The 8-node Gauss-Legendre integral was applied to solve the complicated integral. On the other hand, the phase change value of a grating of certain spatial frequency resulted from the lateral color aberration was analyzed, the expression of the modulation transfer function of the lateral color aberration with discrete spectral of C(656.3 nm), D(589.3 nm), F(486.1 nm) light was derived. Finally, the proposed method was used to calculate the modulation transfer function curves of two fisheye lens systems; and the results were compared with those obtained by Zemax program. The study results show that the proposed method is valid for calculation of a fisheye lens with a moderate/small pupil.