In laser guidance, the optical quality of four-quadrant detector lens determines the accuracy of target positioning. In view of this, a non-contact detection system of the optical quality of the four-quadrant detector lens is designed. The system can detect the optical quality of the four-quadrant detector lens in batches online. First, the laser light source is shaped, expanded, and collimated into a flat-top beam. Then, the image is developed on the frosted glass through the four-quadrant detector lens. Finally, the shape, position, and uniformity of the spot are detected by the non-contact microscopic objective lens with long working distance. The design results show that the system can effectively batch detect the optical quality of the four-quadrant detector lens, thus improving the quality control of the four-quadrant detector lens, and helping to improve the overall quality of the four-quadrant laser guidance detection system.