DDC-JQ electro-vacuum charging valve is a safety valve for vacuum, pump. It is mounted at the intake nozzle of vacuum pump, synchronously opened and closed with the vacuum pump. In case that vacuum pump stops working or power supply is suddenly broken off, valve will be cosed automatically to keep the vacuum system vacuum and the air charged into the cavity of vacuum pump, thus to prevent pump oil from reverse flow that can pollute the vacuum system. Applicable medium can be pure air and noncorrosive gases.