This paper proposes a nonmetric correction method for lens distortion based on the collinear vanishing point constraint. Regarding the error in distortion center positioning, the fundamental matrix of the distortion model and the least-squares method are used to achieve the high-precision positioning of the distortion center. Furthermore, the distortion measure function for the joint measure by the vanishing points and the straight-lines is defined according to the collinear vanishing point constraint, and the Nelder-Mead algorithm is employed for nonlinear optimization. Accurate distortion model coefficients are thereby calculated iteratively. The experimental results show that the proposed method can effectively and accurately correct lens distortion. Moreover, the method is simple and easy to operate and offers high correction accuracy.