At present, the spatial target position detection system based on optical measurement method mainly adopts monocular vision and binocular stereo vision, of which binocular vision benefits from the use of bionic parallax principle, and the spatial relative position of the target can be calculated by optical triangulation, which is widely used. In addition, in view of the complicated image processing process of traditional CCD and CMOS vision cameras, a detection method that combines the principle of binocular vision and PSD sensor to apply to the position of the light spot in space is proposed. The image processing is converted into the signal processing process of the photodetector, and a specific position detection system of the cooperative light spot is built. Experimental results show that the PSD visual phase X and Y direction coordinate fluctuations are within ± 130 μm, and the detection system accurately restores the motion trajectory of the spatial light point in the 160 mm×160 mm×200 mm cubic space at a distance of 1 000 mm, and its positioning error is 4. 35 mm, with each 50 mm increase in depth, the error increases by about 27%, and the average error of the system is 7. 30 mm, with good stability.