Disclosed is a gravity vacuum suction casting forming method. The steps of the method are that: 1) the metal or the alloy is melted with induction in vacuum condition, and electromagnetic stirring refining is carried out; the resistance furnace preheats the pouring mold; 2) after finishing the vacuum refining, the shield gas is pumped in; 3) vacuumize the lower part of the pouring mold, and quickly pour the liquid metal for mold filling; 4) when the mold cavity is full, close the resistance furnace; after being solidified, open the mold cavity, and the required alloy wires or bar materials can be obtained. The invention melts metals or alloy in vacuum, the suction casting process is carried out in shield gas; thus the defects of oxidation and impurity in the process of the metal material forming are avoided, and the pouring mold is fully preheated before mold filling; the problem that the fluidity of the metal gets bad along with the decreasing of temperature and the metal can not fill mold well is solved. Using the method makes the surface performance of the casting wire material and the bar material excellent, and the mass production can be realized.