The invention provides a casting forming weight control method. The casting forming weight control method comprises the following steps that 1, lead melting is conducted, specifically, a lead ingot isput into a lead pan to be melted; 2, pressurizing is conducted, specifically, the interior of the lead pan is pressurized through an air cylinder; 3, material conveying is conducted, specifically, through pressure applied by the air cylinder, liquid lead is poured into a lead mold through a material conveying pipe; 4, forming is conducted, specifically, the liquid lead is cast into a solid grid through the lead mold and a cooling system; 5, discharging is conducted, specifically, the grid after cooling forming is put on an excess material workbench; and 6, excess material removal is conducted, specifically, irregular excess materials of the grid are removed through a cutting device. According to the casting forming weight control method, the lead liquid is poured into the lead mold in anaccelerated mode through pressure action, the grid production efficiency is improved, meanwhile, the weight of the lead poured into the lead mold is controlled more precisely through air pressure, thus, the excess materials of the product grid are decreased, production raw material wasting is avoided, and the production benefits are increased.