The invention relates to a method for determining full shutdown of an air-cooling unit of a transformer by using an analog value and a switching value. The method comprises: (1), a current of an air-cooling power supply inlet wire of a transformer, currents of each fan set and each oil pump set, a power bus voltage of an inlet wire of a transformer cooler and a normally-closed contact state of an inlet wire contactor of the transformer cooler are collected; and (2), an air-cooling control unit of a transformer carries out determination of full shutdown of an air-cooling unit of a transformer according to the collected current of the air-cooling power supply inlet wire of the transformer, the currents of each fan set and each oil pump set, the power bus voltage of the inlet wire of the transformer cooler, and the normally-closed contact state of the inlet wire contactor of the transformer cooler. With the method disclosed by the invention, air-cooling full shutdown determination is carried out by determining an analog value and a switching value in an air-cooling power supply of a transformer; and thus various defects caused by single-way contactor-based determination of air-cooling full shutdown can be overcome. And maloperation and operation failure due to air-cooling full shutdown protection setting of a large power transformer can be solved.