The power of hydraulic lifting system is provided by engine of dump truck to achieve car unloading and return, in order to achieve goods fast and efficient transport. Taking a dump truck lifting system as the research object, the lifting hydraulic cylinder articulated position was taken as the optimize design object, and the virtual prototype model of the system was established. The kinematics and dynamics characteristics of the hydraulic lifting mechanism were analyzed, and the hydraulic cylinder articulated position of the lifting system was optimized. The simulation model of the dump truck rear straight top hydraulic lifting system was established based on ADAMS, and the lifting system was optimized, considering the boundary constraint, no interfere constraint, lifting cylinder maximum pendulum angle constraint, lifting cylinder installed length constraint and maximum diameter constraint and the maximum lifting capacity constraint. The lifting cylinder maximum length minimum was taken as the optimization objective to determine the parameters of the lifting cylinder, and then the lifting cylinder maximum lift force minimum was taken as the goal of lifting mechanism to make optimization, so the best articulated position of the hydraulic cylinder was gotten. Through optimization design, the maximum length is reduced by 145%, and the maximum lift force is reduced by 147%, which provide a strong basis for the design improvement. Finally, the experimental analysis was carried out to verify the accuracy of the theory.