Abstract: In view of the current manufacturing model of launch vehicle pipe sampling and final assembly, it severely restricts the assembly period of the launch vehicle. In this paper, the use of laser scanning method is proposed to build a physical point cloud model of different arrow body. According to the assemble benchmarks based on different rocket body, the data is extracted from the physical point cloud models of different rocket body to establish the datum plane and datum circle center, using benchmark alignment to realize digital assembly of point cloud models of different arrow body, and using coarse matching, fine matching and other algorithms to analyze the benchmark establishment and benchmark alignment. Based on the assembled point cloud model, according to the "point, line, surface" way to establish the catheter model for subsequent processing. The digital pre-manufacture of the carrier rocket sampling catheter is realized sucessfully.