To analyze and control the errors from the single-pulse laser emitted and the multi-beam detectors parallel received, two-dimensional galvanometer sweeping structure of laser three-dimensional imaging system (LTIS) in Chang’e-3, this paper proposed a novel full-link error analysis and simulation method for multi-channel LTIS in which different aspects are considered, including the ranging link error term of multi-beam range channels (systematic and random) and the angular link error term of the two-dimensional galvanometer. Meanwhile, the error decomposition and simulation procedures of systematic/random error parameter items in the full-link LTIS are conducted to satisfy the accuracy requirement of 20 cm for hazard detection and avoidance in Chang’E-3. The experimental results show that errors in the fixed delay, galvanometer encoder, collimation axis and in horizontal axis have the greatest impact on the accuracy of LTIS. Furthermore, different solutions are designed to control these error factors effectively in the proposed manuscript.