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%.