To realize the calibration of a camera and a light plane in the line structured light sensor simultaneously, a calibration method was proposed based on a single plane calibration target which contains a concentric circle and two orthogonal lines passing through its center. Firstly, several images of model plane were captured from different orientations, and the camera parameters were determined via computing conjugated points linearly and were optimized according to the orthogonal constraints. Then, by moving the sensor for several times freely and keeping the light plane intersecting with the concentric circle, the perspective-three-points (P3P) model was implemented, and the 3D coordinates of calibration points on the light plane were computed. Finally, the light plane equation was derived eventually using the least square algorithm. Experimental results indicate that this calibration method has high accuracy, its average measuring accuracy is 0.036 82 mm, and relative error is about 0.277 13%. This calibration method requires only one target to complete the calibration of camera parameters and light plane equation, therefore, the calibration cost is reduced. It is characterized by simple calculation, easy operation and suitable for calibration in fields.