A cross structured light calibration method based on planar targets is proposed to achieve high-precision calibration of line structured light. According to the Blinn-Phong lighting model, it can be inferred that when the laser stripe is projected on the edge of the feature point on a planar target, the cross-section no longer follows a Gaussian distribution, the commonly used center extraction algorithm cannot accurately extract the target. Firstly, morphological operation is used to remove center points at the edges of feature points on flat targets, reducing the error of line fitting from 0. 060 8 pixels to 0. 035 8 pixels, effectively reducing the impact of algorithm extraction errors on calibration results. Secondly, based on Gaussian curve fitting method, correcting the intersection position of the extracted line structured light and auxiliary structured light, based on the Ransac algorithm for line fitting, the results also effectively eliminate points with significant errors caused by uneven lighting and material changes. Experimental results show that the combination of the two methods improves calibration accuracy by 25% , the difference between the three-dimensional coordinates of the center point and the plane equation of the calibration plate is only 4 μm, effectively improve the accuracy of line structure cursor positioning.