Aluminum alloy 50 pump squeeze casting process for the production of: aluminum alloy, mold preparation (cleaning, preheating, spray lubricant), the quantitative metal pouring, the liquid metal pressure, packing, pressure and Casting the top, casting cleaning, heat treatment and so on. 1, the melting of the alloy A356 aluminum alloy melting furnace frequency furnace, resistance furnace insulation. Before pouring, the aluminum liquid should be modified and refined to remove the gas from the molten aluminum, and the microstructure of the alloy is refined to further improve the mechanical properties and machinability of the alloy. The refining agent adopts ZRBI, the refining temperature is 730 ° C., the refining time is 10-15 min, and the refining agent is allowed to stand for 10 minutes before metamorphism treatment. The modifying agent is ZRB4, the modifying agent is added in two times, the residual modifying agent is added after pouring 100 kg, 730 ℃, metamorphic time 8min, the metamorphic agent should be pressed into the depth of liquid slightly stirred. 2, squeeze casting process parameters after repeated tests, the final process parameters identified as: specific pressure 75-95 Mpa; pressure start time 5-8s; extrusion speed 140-156mm / s; dwell time 45-60s; mold Temperature 150-200 ℃; Pouring temperature 620-650 ℃; Quantitative liquid alloy: 6.9kg per spoon, the use of quantitative spoon; Coatings are: oil + graphite or water-based paint. 3, heat treatment process began using A356 typical heat treatment process for heat treatment of castings. The process is: solid solution temperature 525 ℃, heat 10h; aging temperature 230 ℃, heat 6h. Tensile strength can reach 320 MPa (required ≥ 310MPa), but the elongation has been about 2% (requires ≥ 3%). Through process adjustments, increase the solution temperature, reduce the aging temperature, mechanical properties fully meet the requirements. The final heat treatment process: solid solution temperature 535 ℃, holding time 10h; aging temperature 170 ℃, holding time 6h. Squeeze casting production of 50 pump body, and metal casting, low-pressure casting compared to the passing rate of castings from 85% to 96% or more, the craft yield greatly increased.