Abstract: The output voltage of each channel of the four-quadrant tracking system under changing temperature was measured, and a model used to correct the spot center coordinates was established, which was used to compensate the deviation caused by temperature changes. The uncertainty of spot location was reduced via controlling temperature of circuit system operation. According to the photoelectric detection system signal processing way, center coordinate of light beam may be calculated with intensity magnitude of received light pulse of each quadrant. Output characteristics of the four-quadrant tracking system were also tested, the linear operation range of the system was determined which ensured the spot on the best measurement area of the four-quadrant detector. Under circuit system environment temperature controlled, the tracking resolution is 1 m, which is dependent on the step accuracy of stepper motor which is controlled by microcomputer.