Parallax has a significant impact on the observation and aiming of a telescopic system.The traditional parallax detection methods mainly rely on the subjective interpretation of human eyes and the detection accuracy is low,and the parallax adjustment quantity cannot be given quantitatively.Based on the prototype improvement of parallax detection by theodolite,a new parallax detection method for the telescopic system with two optical paths is designed.It receives the outgoing rays on both sides of the objective lens of the telescopic system through two optical paths respectively,detects the angular parallax of the telescopic system by relying on image interpretation technology,and obtains the line parallax of the telescopic system through formula.The mathematical relationship between the offset of cross division center and the parallax value of image interpretation is established according to the physical model.The system can realize the parallax detection of a wide range of optical calibers with high efficiency,high precision,automation and other advantages,and the detection accuracy is as high as 11.9″.