The invention discloses a high-pressure gas bottle mouth valve with a heat storage device and a gas cylinder charge and discharge temperature control method. A valve body in the bottle mouth valve isprovided with a vertical gas exhaust port and a horizontal gas inflation port for gas circulation, the valve body further comprises a control port and a control channel, and the gas exhaust port and the gas inflation port are connected through the control channel to form a gas channel; a valve rod penetrates through the control channel through the control port, the top of the valve rod is connected with an operating handle, the valve rod at the control port and the valve body are sealed by gland packing, and a packing gland is used for tightly sealing packing; the periphery of the middle of the valve rod is in threaded connection with the valve body, and the tail end of the valve rod is connected with a valve core at the position of the gas exhaust port; and the heat storage device is assembled at the position of the inlet of the air inflation port, and the heat storage device is filled with two phase-change media to achieve the functions of heat storage and heat release. According tothe high-pressure gas bottle mouth valve, the phase-change heat storage device is introduced into the bottle opening valve of a gas cylinder, so that the gas cylinder can be effectively prevented frombeing charged, the gas temperature of the gas cylinder is too high or too low, the use safety of the gas cylinder is ensured, and the energy consumption of the gas cylinder during gas filling can beeffectively reduced.