A detection method for measuring the ability of opto-electronic tracker which captures low-contrast target is proposed. With infinite target source of adjustable contrast as detection device, optical reference target whose contrast can be accurately measured is provided for detected opto-electronic tracker, which is particularly used for testing acquisition ability of opto-electronic tracker for low contrast target. Principle and composition of the detection device, calibration method for target′s contrast are introduced, and detection results are analyzed. Through the research of the detection method, it is realized to evaluate the ability that the whole opto-electronic tracker captures low contrast target. The detection method involves performance of optical system, performance of photoelectric receiver, image processing circuit, software, signal-to-noise ratio and related indexes which influence target contrast, which reflect tracking performance of television tracker all-sidedly and truthfully.