A heat dissipation structure of the door leaf of an LED display box, comprising a box frame and a box door leaf, wherein the box frame comprises an outer frame and a connecting frame,the outer frame is fixedly arranged around the connecting frame,a plurality of LED display modules are fixedly connected to the connecting frame, and the backs of the LED display modules uniformly face the rear of the box frame,the LED display modules are installed in the box frame by the connecting frame,a heat collection cavity is simultaneously formed in the box frame and on the backs of the LED display modules, when working, a number of the LED display modules are energized and emitting light, and the light is irradiated forward, and the heat generated by the operation of the LED display modules is concentrated in the heat collection cavity,the box door leaf has two states: open and closed, when the box door leaf is in the open state, the heat collection cavity is opened, at this moment, a number of the LED display modules are exposed, when the box door leaf is in the closed state, the heat collection cavity is closed, at this moment, the heat collection cavity is sealed and waterproofed by the box door leaf, characterised in that the box door leaf comprises an outer door leaf plate and an inner lining board, wherein the inner lining board is arranged on the inner side of the outer door leaf plate, and at the same time, a ventilation and heat dissipation channel is formed between the inner lining board and the outer door leaf plate,wherein the ventilation and heat dissipation channel is in communication with the heat collection cavity,wherein the ventilation and heat dissipation channel comprises an air inlet and an air outlet, wherein the air inlet is in communication with the heat collection cavity, and the air outlet is arranged on the outer door leaf plate,wherein the inner lining board comprises an inner side and an outer side, and the ventilation and heat dissipation channel is located between the outer side of the inner lining board and the inner side of the outer door leaf plate,wherein the box heat source part is fixedly connected to the inner side of the lining board, and at the same time, the box heat source part is located in the heat collection cavity, wherein, the air in the ventilation and heat dissipation channel flows in from the air inlet, and then flows out from the air outlet, during this process, part of the heat generated by the operation of the heat source part of the box is directly transferred to the heat collection cavity, and then the airflow in the ventilation and heat dissipation channel is used for ventilation and heat dissipation, the other part of the heat generated by the operation of the heat source part of the box is directly transferred to the lining board, and then the lining board is ventilated by the airflow in the ventilation and heat dissipation channel, and an air inlet channel is formed between the liner board and the outer door leaf, and is communicated with the heat collection cavity, wherein the air inlet channel comprises an inlet and an outlet, wherein the inlet is arranged on the outer door leaf plate, and the outlet is arranged on the lining board such that when the airflow flows in the air inlet channel, the lining plate is capable of being ventilated and cooled.