The invention discloses a local pressurizing structure of a high-air-sealed die-casting die. The local pressurizing structure comprises a die body and a cavity insert; the cavity insert is fixedly arranged in the die body, an oil cylinder is arranged on the die body, a guide sleeve with a cavity in an internally-through manner is arranged on the cavity insert, a push rod on the oil cylinder penetrates the die body to be placed in the cavity insert, a pressurizing rod is arranged at the free end, the pressurizing rod is arranged in the guide sleeve in a penetrating manner, and the free end of the pressurizing rod corresponds to the cavity; and the pressurizing rod is additionally arranged at the local position of the cavity of the die-casting die, the structural manner of material liquid pressurizing is carried out on the local position of the cavity of the die-casting die, the problems of internal shrinkage, shrinkage porosity and the like generated by reasons of the small wall thickness, insufficient material liquid flowing pressure and the like in the die-casting process of a die-casting part are solved, and the local pressurizing structure is simple in structure, flexible and smooth in action and obvious in pressurizing effect.