In order to study indirect squeeze casting process, we selected ZL101 aluminum alloy with porosity as indicators and analyzed the effect of process parameters of pressure, die temperature and proportionality factor on porosity. Box-Behnken design of experiment have been developed to design response surface experiment and regression model of the relationship between the indirect squeeze casting process parameters and porosity have been established. ANOVA result shows that the fitting effect of the experimental results and the mathematical model is good. The effect of die temperature and pressure on porosity has certain interaction but the effect of die temperature and proportionality factor or the effect of proportionality factor and pressure on porosity does not exist significant interaction by analyzing response surface of interaction of various factors. Due to the applied pressure, the congealed metal shell will happen uneven plastic flow by metallographic testing analysis of the edge of sprue in gating system parts.