Abstract: Based on the Carreau apparent viscosity model and the finite element software Anycasting, the semi-solid extrusion casting technology of AlSi7Mg aluminium alloy support was studied. The influences of three main technological parameters on the filling and solidification process of semi-solid slurry and casting properties were analyzed and discussed by simulation results, and the semi-solid extrusion casting test of the supports was carried out by experimental method. The results show that the reasonable parameters of the semi-solid extrusion casting of aluminum alloy support are injection velocity of 0.04-0.3m/s, casting temperature of 585-595℃, and initial die temperature of 200-250℃. Within this parameter range, the aluminum alloy supports with better quality can be obtained.