Abstract: The objective of this study was to solve the positions of pin joints of an eight-bar mechanism of a wheel loader using simulation optimization. The parametric simulation model of the working mechanism of a wheel loader was established with Automatic Dynamic Analysis of Mechanical System (ADAMS) software. The optimization models, including design variables, objective functions and constraint functions, were presented according to the design requirements. Multi-objective functions were transferred into a single objective function in the Function Builder of ADAMS. Changing the values of weighted factors, different optimization results were obtained. Optimization results showed that the performances of parallel lifting and digging force were improved. The optimization method based on simulation presented in this study was visual and easily operable for completion of the design.