According to the requirement of target range test of photoelectric sights at present stage, aiming at the defects of non-quantitative, large error and low efficiency of traditional parallax detection methods, a parallax detection method based on sine-like micrometric method is proposed. Quick and quantitative test of photoelectric sight parallax can be realized by the proposed method. Taking the fast-observing principle of the traditional pendulum method, sine-like micrometric method is used to realize the quantitative data acquisition, and an improved parallax detecting device with sine-like micromotion subdivision mechanism is constructed. Three kinds of typical optoelectronic sights samples are selected, and the test effect comparison experiments of four kinds of parallax test methods are conducted in detail. The results show that the parallax detection method and device based on sine-like micrometric method can not only ensure the testing accuracy of 0.01',but also meet the requirement of high efficiency and high precision in the target range test of photoelectric sights, and the test result is superior to other traditional parallax detection methods.