To achieve a simple and fast calibration of parameters for three-dimensional imaging system with structured light, a method of obtaining a large number of calibration data using a homography matrix is presented. First, the image coordinates and the corresponding world coordinates of the rectangular corner points on the left and right sides of a stereo target are obtained, and the homography matrices of the left and right sides of the target surface from the image coordinates to the world coordinates are then calculated respectively. Next, all the pixels in the rectangular frame of the stereo target in the image are applied to the calculated homography matrix to obtain the corresponding world coordinates. Finally, we calibrate the three-dimensional imaging system using the image coordinates of nearly all the pixels on the target surface of the stereo target in the image and the corresponding world coordinates. A stereo target corresponding to the proposed calibration method is designed. Based on the stereo target, the three-dimensional imaging system with structured light is calibrated and experiments are carried out using the calibrated system. The experimental results show that the calibration method has high calibration accuracy, the reconstructed three-dimensional point cloud image has a good visual effect, and the calibration process is simple, which reduces the cost of calibration and is valuable for practical applications.