By Simufact.forming finite element simulation software, the thinning ratio of the first pass, conical angle of die and ironing speed were taken as the independent variables, and the deviations of outer roundness and wall thickness of cylindrical part were taken as the optimization objective, the ironing process was simulated, and the orthogonal experiment with three levels and three factors was designed. Based on the grey correlation analysis, the correlation coefficient and correlation degree of each process parameter to the dimension accuracy [JP2]of cylindrical part were calculated, and the optimal combination of process parameters was obtained by multiobjective optimization. The results show that when the thinning ratio of the first pass is 70%, the conical angle of die is 10° and the ironing speed is 10 mm·s-1, the dimension accuracy [JP]of cylindrical part is higher in the ironing process. The order of the influence of ironing process parameters on the dimension accuracy of cylindrical part is as follows: thinning ratio of the first pass>conical angle of die >ironing speed. Furthermore, the [JP2]verified experiments were conducted. And the relative error between the simulation results and the experimental results is less than 10%. It is proved that the finite element simulation is of good reliability, which can be described as the guidance for the actual production.