Disclosed is a constant quantity control nebulization device including a main body, a nebulization module, a fixing plate and a rotary ring, and the device is installed to a container that contains a liquid to be nebulized. A first liquid storage space with a predetermined volume is defined at the top of the main body, and the nebulization module is installed in the main body and interconnected to the first liquid storage space, and the fixing plate is fixed onto the main body and has a first through hole, the rotary ring is sheathed on the top of the main body and axially coupled to the fixing plate, and the rotary ring has a second through hole corresponding to the first through hole. The consumption of the liquid to be nebulized can be controlled by rotating the rotary ring to improve the convenience of operation significantly.
