基于改进的液压缸阶梯杆模型，对细长型液压启闭机液压缸筒及活塞杆的挠度进行了计算分析，考虑了液压缸安装角度、缸筒与活塞杆配合间隙、液压缸活塞杆自重以及油液质量对杆轴横向变形的影响; 依据固体力学基础理论对缸筒、活塞杆的受力与变形进行计算推导，通过建立和求解挠度方程获得了液压缸筒、活塞杆挠度的解析计算方法，并结合工程实际给出了应用算例．结果表明，与有限元计算方法相比，文中方法的计算误差在 5%以内．

In this paper,first,the flexural deflections on the cylinder and the piston rod of slim hydraulic hoist arecalculated and analyzed based on an improved ladder pole model,and the effects of some parameters,such as theinstallation angle of the cylinder, the fit clearance between the cylinder and the piston rod, the dead load of the pis-ton rod and the oil mass,on the transverse deformation of the shaft,are taken into consideration. Then,accordingto the basic theory of solid mechanics,the load and deformation of the cylinder and the piston rod are calculated,and an analytical expression describing the deflection on the cylinder and the piston rod is deduced by establishingand solving deflection equations. Finally,an engineering instance is given,and the results show that the proposedmethod is superior to the finite element method because it is of a small calculation error of less than 5%.