Now, the structure of secondary separation type mold for metal die-casting forming is shown as follows: (I) The screw tensioner spring splitting cross tie is fixed for secondary type separation type, when the mold is opened, the mold machine is opened and the closing mold system moves after the moving type part. According to the action of the spring, the mold is firstly divided by the secondary type separation surface of the fixed mold part, and the intermediate plate moves from the movable type, and then the main runway is led out. The intermediate plate of the mold stops moving when the nut of the movable mold part touches the plate between it. The pipe tensioner movable mold continues to move to the rear and the main runway separation surface is opened; the casting is wrapped by the neutron, at which time the solidified material of the hot water injection system extends itself at the solidification port and afterwards falls out of the mold autonomously at the auxiliary type separation surface of the fixed mold section.