The invention provides an artificial satellite laser ranging system. The artificial satellite laser ranging system is characterized by comprising a ranging control computer, a laser, a transmitter-telescope, a receiving telescope, a data collection computer, an event timer, a range gate circuit board, an artificial satellite tracking and pointing device and a single-photon avalanche diode. By means of the artificial satellite laser ranging system, the event timer records the dominant wave moment and the return wave moment, the signal to noise ratio of the system is greatly improved by application of a high-resolution-ratio and high-precision range door, then the effective return wave data size is improved, and the ranging precision and ranging capacity of the system are improved remarkably.