Based on the tool of the ANSYS Workbench software,the modeling of three-dimensional entity,meshing and dealing with loads and constraints was done on the pipelayer's boom,and the finite element analysis of pipelayer's boom in three basic conditions was carried out.Taking the width,height and thickness of the boom as optimal variables,the minimum mass of the boom as the design objective,the optimal design of the boom was conducted,and the material consumption of making boom was significantly reduced.And the results will be the theoretical basis of the design and improvement of pipelayer'boom.