Abstract: When the pumping unit runs at low speed, the displacement of the suspension point changes slowly, which increases the difficulty in calculating the displacement amount and identifying the displacement direction during the displacement test process, resulting in an increase in the error rate of cable displacement and acceleration displacement data. In order to get rid of the influence of the running speed of the suspension point and realize fast, accurate and convenient slow-stroke displacement test, a slow-stroke displacement test method based on photoelectric pixel recognition was designed. Using the photoelectric mouse chip system as the probe, by irradiating, sampling, and analyzing the polished rod, with the help of the high resolution and fast scanning function of the mouse chip, the analog quantity detection for displacement was converted into the state quantity detection and the digital accumulation of trace displacement for the presence or absence of displacement, obtaining the displacement information consistent with the suspension point. The slow-stroke pumping unit well was tested with this method, and the displacement data that meets the engineering requirements were obtained. The field test has proved that it is feasible to apply the photoelectric pixel recognition and positioning technology to the displacement test of the polished rod of the pumping unit, which verifies that this technology is not affected by the operating speed of the pumping unit, is easy to process and use data, and produces accurate data.