To provide a filling method of quick lime, in which activity of the quick lime is not susceptible to lowering caused by moisture or carbon dioxide gas contained in force-feeding air when the quick lime is transferred from a tank truck to a quick lime silo by the force-feeding air.

In the filling method of quick lime, when the quick lime in a tank 2 of the tank truck 1 is transferred to the quick lime silo 4 on the ground by the force-feeding air, exhaust air in the force-feeding air discharged from the quick lime silo 4 is guided to an air inlet port of an air compressor of the tank truck 1 through a circulating line, so that the exhaust air is circularly reused as the force-feeding air for the quick lime. Accordingly, the quick lime is transferred from the tank truck 1 to the quick lime silo 4 by the force- feeding air, while reducing an amount of outside air entering into the force-feeding air.