In modern society, high-rise buildings are everywhere, and urban fire protection is also facing many challenges. The primary problem is the fire protection and rescue of high-rise buildings. Therefore, there is always a demand for large ascending platform fire trucks in China. Collapsible boom structure is a common structure of fire truck with ascending platform. The performance of collapsible boom luffing process largely depends on the layout of each hinge point of luffing mechanism. In this paper, the hinge point position of the key structure of the folding arm type 72m ascending platform fire truck is optimized, and the original structure layout is improved, so that the variable amplitude hydraulic cylinder has less force, and the safety performance of the folding arm is improved. In this paper, the kinematic and dynamic models of boom amplitude are established, and two optimization methods, genetic algorithm and SQP algorithm, are adopted to optimize, and the two optimization results have a certain degree of improvement in performance compared with the original layout.