In order to improve the measurement accuracy of the laser displacement sensor, the laser triangulation displacement measuring system is established. The spot subdivision location algorithms of the system are studied, such as the Gaussian curve fitting, traditional gray weighted centroid and gray square weighted centroid. First, according to the principle of laser triangulation, the displacement measuring system is built. Then, objects are moved by the high-precision motorized stage, obtaining multiple sets of image data. Next, these data respectively are processed by the above several algorithms to obtain the corresponding coordinates of the laser spot, the system is calibrated respectively. Finally, comparing the displacement of calibration results calculating with the actual displacement. The results show that: those data that are processed by the gray square weighted centroid are used to calibrate , calculating the minimum error, and is 71.1 μm. It concludes that gray square weighted centroid is an ideal location segmentation method, which is not only simple and easy to implement, but also has a higher positioning accuracy.