Abstract: According to characteristics of friction stir welding,the dynamic heat source model for characteristics of friction stir welding process has been established based on fully considering the friction generating heat between the each parts of the tool and the joining plate,and joining plate friction coefficient with the temperature changing law in the friction stir welding process. By which finite element simulation has been studied for friction stir welding of aviation aluminum alloy sheet. By comparison with simulation results and test results,it could be verified that the established dynamic heat source model and finite element analysis process are reasonable. The simulation results show that the friction stir welding residual tensile stress is concentrated in the joint region,the maximum residual tensile stress appears in the middle of the joint region,and the residual compressive stress appears at the both ends in the joint region and other areas.