An exemplary atomizer includes an atomizing assembly and a liquid supply. The liquid supply includes a connection end. The atomizing assembly is detachably connected to the connection end. The connection end defines at least one liquid outlet, through which the tobacco liquid flows into the atomizing assembly. The atomizing assembly further includes a sealing element and an elastic element. The sealing element is configured for sealing the liquid outlet when in a first position, and the elastic element abuts against the sealing element. When the atomizing assembly is connected with the liquid supply, the atomizing assembly is configured for driving the sealing element to move to a second position where the liquid outlet is opened. When the atomizing assembly is detached from the liquid supply, the atomizing assembly is configured for driving the sealing element to return to the first position where the sealing element seals the liquid outlet.