Designs an orthogonal experiment to analyze the effect of process parameters on the mold core deformation in the hollow aluminum extrusion process, and makes numerically simulation with the finite element software HyperXtrude. The results indicate that the effect of die preheating temperature on the mold core deformation is largest and the extrusion speed is the second, while the billet preheating temperature is smallest. The results provide a reference for the aluminum extrusion process parameter optimization.