In order to achieve three-dimensional reconstruction in structured light system,aiming at the issues of traditional calibration approach,such as complicated structure,cumbersome calibrating proces s,a two-stage calibration method based on ray beeline tracking is proposed.Firstly,by calibrating respectively each detection point in a pattern image projected on the front and rear planes at projection side,the ray equation at the projection side is esta b lished.Then,the ray equation at the reception side (CCD) is established by obtaining respectively the target points on the front an d rear planes.During three-dimensional measuring,a point in light field maps two points located on the front and rear planes at the projection and reception sides.A straight line is established by connecting two points,respectively.Three-dimensional coordinates by solving intersection point of two space lines can be achieved.This paper has analyzed the system structure error,which mainly comes from the angle deviation and horizontal offset,and the error solution is presented.The experimental results show that co mpared with traditional calibration method based on pinhole model,the presented method does not need to consider the imaging model and its parameters,which is concise and efficient. The relative error of the depth of field generated by the calibration is less th an 0.2%,which can improve the geometric calibration accuracy of structured light systems.