The invention discloses a lithium battery pack heat dissipation device and a control method thereof. The lithium battery pack heat dissipation device consists of a box, air door blades, a lithium battery pack, a temperature sensor, an actuator, a controller and a vehicle speed sensor. The air door blades are disposed at one end in the box, the lithium battery pack is disposed at the other end in the box, air current flows into the box through the air door blades to cool the lithium battery pack in the box, the detection end of the temperature sensor is connected to the lithium battery pack, the output end of the temperature sensor is connected to the controller, the controller is respectively connected to the actuator and the vehicle speed sensor, the actuator is connected to the air doorblades and is used for driving the air door blades, and can control the flow of air current flowing into the box, the controller is used for reading the vehicle speed signal of the vehicle speed sensor and the temperature signal provided by the temperature sensor and performing corresponding calculation, and then transmitting a corresponding driving signal to the actuator. The lithium battery packheat dissipation device and the control method provided by the invention can calculate and control the air volume in real time according to the actual working condition, optimize the heat dissipationefficiency, and improve the performance and safety of the lithium battery pack.