The effects of different pressures and pouring temperatures on the microstructure and properties of AZ91D magnesium alloy prepared by squeeze casting technology were studied, and better process parameters were explored to provide guidance for the production of high-quality magnesium alloy castings. The results show that at the same pouring temperature, with increasing extrusion pressure, the volume fraction of the second phase presents a slightly decreasing trend, the eutectic structure distribution on the grain boundary becomes increasingly discontinuous, and the α-Mg phase decreases gradually. At the same extrusion pressure, the grain size of the alloy gradually grows with increasing pouring temperature. The comprehensive mechanical properties of extrusion casting obtained at 730 ℃ pouring temperature and 80 MPa extrusion pressure are the best, with the density reaching the highest value of 99.78%, which is 1.4% higher than that of the raw materials. The tensile strength increases by 81.1% from 121.2 MPa to 219.5 MPa, and the elongation increased by 300% from 1.6% to 6.4%.