The invention relates to an inhaler and an atomizing subassembly thereof. The atomizing subassembly of the inhaler comprises a carrier and a suction nozzle, wherein a liquid storage cavity is formed in the carrier; a liquid injection hole which is connected with the liquid storage cavity is formed in one end of the carrier; the suction nozzle comprises a body and an extension portion; the body is fixedly connected with the extension portion; the extension portion extends into the liquid injection hole; an end of the extension portion is positioned in the liquid storage cavity; a liquid injection channel is formed in the extension portion; and the bottom of the liquid injection channel is elastic and can be pierced so as to be connected with the liquid storage cavity. During liquid injection, a liquid injection needle penetrates in the liquid injection channel and pierces the bottom of the liquid injection channel, so that liquid can be injected into the liquid storage cavity. When the liquid injection needle is pulled out, the bottom of the liquid injection channel can be closed owing to elasticity of the bottom of the liquid injection channel, and liquid injection can be carried out even if the suction nozzle is not pulled up.