Electric vehicle battery thermal protection device

The invention provides an electric vehicle battery thermal protection device, which comprises a battery box body, a Stirling engine, a micro water pump and a heat exchanger, wherein the battery box body comprises condenser tube interlayers arranged at intervals and a battery module accommodating chamber; each U-shaped condenser tube is arranged in each condenser tube interlayer; the water inlet ofeach U-shaped condenser tube reaches out of the battery box body to be connected with a condensing water inlet general tube; the water outlet of the U-shaped condenser tube reaches out of the batterybox body to be connected with the condensing water outlet general tube; the condensing water outlet general tube is connected with the water inlet of the micro water pump; the water outlet of the micro water pump is connected with a heat medium inlet of the heat exchanger; the heat medium outlet of the heat exchanger is connected with the condensing water inlet general tube; the hot cylinder of the Stirling engine is attached to a heat conducting plate at the top of the battery; and the power output rotation shaft of the Stirling engine is connected with the power input rotation shaft of themicro water pump. The device automatically completes hot and cold cycling, adjusts a flow rate, completes heat recovery, and improves the battery life and the safety performance.