A cartridge includes a cartridge housing, an atomizing head, and a sealing member. A liquid storage cavity for storing e-liquid is formed inside the cartridge housing. The atomizing head is located at one end of the cartridge housing, and the sealing member is located at the other end of the cartridge housing opposite to the atomizing head. The atomizing head is in communication with the liquid storage cavity and the outside. When a liquid injection needle is used to inject liquid into the cartridge, the liquid injection needle pierces the sealing member and extends into the cartridge housing to inject e-liquid into the liquid storage cavity. The air in the liquid storage cavity is discharged out through the end of the cartridge housing with the atomizing head. After the liquid injection needle is pulled out, the sealing member will form a self-sealing at the pierced position.