The invention teaches an automatic discharge device for a lithium bromide absorption chiller unit, comprising an automatic pump apparatus, a pump chamber, a gas-liquid separation chamber, and a gas storage chamber. A valve F1 is disposed at the outlet line of the liquid pump. A valve F2 and a gas discharge and liquid feed line disposed between the liquid pump and the valve F1 are connected to the gas storage chamber. A valve F3 is set on the gas duct and liquid return line between the gas storage chamber and the gas-liquid separation chamber. A liquid choke self-closing discharge rubber ball valve, a one-way spring discharge valve, and additionally, an electromagnetic valve or a motorized valve are set on top of the gas storage chamber. The invention simplifies effectively the chiller construction and increases operational reliability.