A metal forming apparatus includes a smelting device, a molding device, an injection device and a vacuumizing device. The smelting device defines a smelting chamber, and includes a rotatable crucible and a heating unit both disposed within the smelting chamber. The molding device defines a molding chamber sealedly communicated with the smelting chamber. The injection device includes a charging barrel assembly sealedly disposed at a joint between the molding device and the smelting device and an injection unit sealedly connected with the smelting device. The vacuumizing device is sealedly connected with the smelting device and the molding device respectively so as to vacuumize the smelting chamber and the molding chamber.