3D imaging LiDAR technology provides a new technical way for spatial geographic information acquisition and target stereo detection. The new generation of 3D imaging LiDAR characterized by multi-beam parallel transceiver and single photon array detection can improve radar detection sensitivity, laser imaging frame rate and imaging efficiency, so as to realize long-distance and fast laser 3D imaging. In the 3D imaging LiDAR system, the transceiver alignment accuracy between the laser divergence angle and the receiving field of view needs to be in order of angular seconds. With the increase of system beams, the transceiver alignment of tens or even hundreds of beams is the difficulty of system design and adjustment. This paper focuses on the problem of multi-beam transceiver alignment, designs the transceiver optical system based on diffraction beam splitting and fiber array, puts forward a transceiver beam matching method of multi-beam LiDAR, analyzes and simulates the transceiver matching error source of this method and the influence of temperature on it in detail. The experimental results show that the matching method in this paper can achieve the matching error of 64 beams better than 10 μrad, and the total transceiver mismatch in the working temperature range is better than 20.78 μrad, which meets the transceiver matching margin of 25.5 μrad in the design of the system. The system has good adaptability to the ambient temperature and has a good engineering application prospect.