In view of the Luffing Jib tower crane jib metal structure self weight, complex calculation model etc. APDL language in ANSYS has been used to establish the model of finite element analysis of luffing boom structure optimization. With the lightest weight as the optimization goal, the stress relative concentration of the chord and connecting rod was selected as the optimization object for the lightweight design of jib. The optimized section size of most rods of the previous scheme was decreased, the jib mass quality was reduced 15699.6N about 15.6% of the weight of the original jib. After optimization, the maximum stress of the jib was reduced from 206.33MPa to 174.63 MPa, the vertical deflection was reduced from 185.14 mm to 127.51 mm. As compare to the original scheme, the structural stress distribution of optimized scheme is more uniform. All the strength and stiffness constraints could be met under various load conditions, the design of jib has been effectively improved and the goal of lightweight has been achieved.