The existing distance ranging systems based on the method of measuring phase do not provide information of the azimuth angle and elevation angle to achieve the target tracking, so it makes this system′s application limited. In response to this phenomenon, under the conditions of not considering echo spot of non-uniformity and noise, the idea of using laser ranging system based on the receiver of four-quadrant APD to achieve tracking was proposed. Through theoretical analysis and simulation test, its result show that, the amplitude information extracted from the four quadrant signal′s FFT, can calculate the azimuth angles and elevation angles; so in theory ranging system based on phase method on the conditions of not needing auxiliary equipment to provide information, can achieve automatic tracking.