||In the structured light 3D measurement system, calibration is the key to the measurement accuracy. However, traditional calibration methods for projector are either too complex or inaccurate. Therefore, the paper proposes a simple and accurate method to calibrate the projector. In this method, the calibration points in the camera image plane can be mapped to the projector according the homography of the planar projection. In addition, an error surface compensation (ESC) method is developed to minimize mapping errors caused by lens distortion of the camera and projector. As a result, the projector can be calibrated with the same method of the camera. Experiments are conducted to verify the effectiveness of the proposed method.