The direct linear transformation (DLT) based on the ideal perspective transformation model can obtain the mapping matrix between the two-dimensional (2D) image coordinates and the three-dimensional (3D) coordinates by solving the linear equations. The method is simple and fast,but it does not take the effect of lens distortion into consideration. In order to correct the distortion in an easy way,this paper takes full account of the lens distortion on the basis of coplanar point linear solution. After initial parameters determined according to the camera information,transformation matrix and distortion coefficient are modified continuously by least-squares method to obtain the optimal parameters,and use data points pair of different location distribution to verify that the distortion coefficient calibrated by the method is relative independence. Finally,square image obtained by the camera was selected and corrected using the distortion coefficient gained by the above-mentioned method. The results have improved significantly and verified the validity of the method.