An atomization device and a cleaning method thereof are provided. The atomization device includes a jar portion and a host device. The jar portion is movably assembled with the host device and includes a nozzle portion and a container portion. The nozzle portion communicates with the container portion and is provided with an atomizer disposed therein. The atomizer is coupled to the host device. The cleaning method includes the steps of: assembling the jar portion and the host device and turning on the host device； determining whether the container portion contains a liquid； entering a safe mode if the container portion does not contain the liquid or determining whether the nozzle portion contains the liquid if the container portion contains the liquid； and entering an atomization mode if the nozzle portion does not contain the liquid or entering a cleaning mode if the nozzle portion contains the liquid.
