The invention provides a battery pack heat dissipation device and method thereof, and a vehicle. The battery pack heat dissipation device comprises a heat dissipation box body, a temperature sensor and a controller; the heat dissipation box body is used for installing the battery pack; one end of the heat dissipation box body is provided with an air inlet, and the other end is provided with an airoutlet, and the air outlet is provided with an adjustment mechanism for adjusting the size of the air outlet; the temperature sensor is used for detecting the battery temperature at the air inlet andthe air outlet of the battery pack; and the controller is connected to the temperature sensor and the adjustment mechanism of the air outlet separately. The temperature sensor detects the battery temperature at the air inlet and the air outlet of the battery pack; the controller judges whether the battery temperature difference between the air inlet and the air outlet reaches a preset temperatureor not, and controls the adjustment mechanism to adjust the size of the air outlet to change the air flow rate at the air outlet position; therefore, the heat dissipation performance of the area is improved; the battery pack temperature imbalance caused by the cooling airflow rising due to the internal temperature of the battery pack is restricted; the temperature uniformity of the battery pack is ensured while heat dissipation; the structure is simple; and the effect is obvious.