Abstract: In order to determine the optimal die casting technological parameters of A356 alloy bracket, three methods, including numerical simulation of forming process, Taguchi orthogonal DOE (design of experiment)and signal to noise ratio analysis, were applied. Taking the minimum porosity and the secondary dendrite arm spacing (SDAS) as the optimization index, theoretical matching and optimization were carried out for the key die casting process parameters, including die initial temperature, aluminum liquid casting temperature, punch injection velocity and die holding pressure.The results show that the optimized process parameters are as follows: the initial die temperature is 275℃, the casting temperature is 630℃, the injection velocity is 0.5m/s, and the holding pressure is 50 MPa. Using optimization process parameter combination can reduce the shrinkage and porosity of the brackets.