Aerosol generating device and atomizer and main machine thereof

The utility model provides an aerosol generating device and an atomizer and a main machine thereof, the main machine comprises a main machine body, the main machine body comprises a shell and a support, a mounting space is formed in the shell, the support is arranged in the mounting space and matched with the shell to form a containing cavity, and the atomizer of the aerosol generating device is inserted into the containing cavity; the host electrode assembly comprises a first host electrode, a second host electrode and a third host electrode, the first host electrode is arranged on the side, close to the containing cavity, of the shell, the first host electrode is in a strip shape and extends in the opening direction of the containing cavity, and the second host electrode and the third host electrode are arranged on the support; the mounting heights of the second host electrode and the third host electrode in the opening direction of the containing cavity are different, so that when the atomizer is inserted