Based on the long-range pulsed laser heterodyne detection system, the expression of signal and noise of the system is deduced. The matched filtering algorithm processing of the pulsed laser heterodyne detection system is given. The detailed application process of matched filtering technique in target detection of medium-range missiles and international space station is simulated. The influence of the target range, the scattering cross section area and the digital sampling rate on the detection capability is analyzed. The simulation results show that, under the digital processing capability of 100 MHz sampling rate, the Monte Carlo simulation of 500 matching filtering process is carried out. For the medium-range missile with the scattering cross section area of 5 m 2 and the distance of 100 km, the carrier-to-noise ratio of echo signal is 3.29 dB, the carrier-to-noise ratio of echo signal after matched filtering is 25.13 dB, the signal strength increases 152 times, the range accuracy is 27 m and the range rate accuracy is 0.17 m/s. For the international space station with the scattering cross section area of 100 m 2 and the distance of 500 km, the carrier-to-noise ratio of the echo signal is -6.12 dB, the carrier-to-noise ratio of the echo signal after matched filtering is 18.49 dB, the signal strength increases 289 times, the range accuracy is 117 m and the range rate accuracy is 2.1 m/s. The smaller the target range is, the larger the radar cross section area is, and the higher the digital sampling rate is, the stronger the ability of the matched filtering to extract and enhance the signal is.