An electronic cigarette, comprising: a mouthpiece assembly, the mouthpiece assembly comprising a mouthpiece and a mouthpiece cap covering the mouthpiece; an atomizing assembly, the atomizing assembly comprising a limit cover, a heating wire, a silicone support, and joints; and a battery assembly, the battery assembly comprising a rotatable cover, a silicone seal, a seal ring, a cartridge, a silicone connector, a battery cell, a pneumatic switch, a silicone base, and a base sleeve; wherein: the mouthpiece assembly is disposed on the atomizing assembly; the atomizing assembly is disposed in the battery assembly; the heating wire is disposed in the silicone support; the silicone support comprises a bottom end which is provided with two holes; the joints are inserted in the two holes, and two pins of the heating wire are fixed in the silicone support via the two joints; the silicone support is disposed in the limit cover; the silicone connector is disposed in the cartridge and connect and fix the atomizing assembly; the pneumatic switch is disposed in the silicone base, and positive and negative electrodes of the pneumatic switch are connected to positive and negative electrodes of the battery cell, respectively; the battery cell, the pneumatic switch, and the silicone base are disposed in the cartridge; the cartridge comprises an e-liquid tank and an e-liquid inlet communicating with the e-liquid tank; the rotatable cover is adapted to cover the e-liquid inlet; the base sleeve is sheathed on the cartridge; the cartridge comprises a joint pin adapted to connect to the mouthpiece; the seal ring is sheathed on the joint pin of the cartridge; the silicone seal is disposed on the cartridge; the rotatable cover is rotatably disposed on the cartridge and covers the silicone seal. a mouthpiece assembly, the mouthpiece assembly comprising a mouthpiece and a mouthpiece cap covering the mouthpiece; an atomizing assembly, the atomizing assembly comprising a limit cover, a heating wire, a silicone support, and joints; and a battery assembly, the battery assembly comprising a rotatable cover, a silicone seal, a seal ring, a cartridge, a silicone connector, a battery cell, a pneumatic switch, a silicone base, and a base sleeve; the mouthpiece assembly is disposed on the atomizing assembly; the atomizing assembly is disposed in the battery assembly; the heating wire is disposed in the silicone support; the silicone support comprises a bottom end which is provided with two holes; the joints are inserted in the two holes, and two pins of the heating wire are fixed in the silicone support via the two joints; the silicone support is disposed in the limit cover; the silicone connector is disposed in the cartridge and connect and fix the atomizing assembly; the pneumatic switch is disposed in the silicone base, and positive and negative electrodes of the pneumatic switch are connected to positive and negative electrodes of the battery cell, respectively; the battery cell, the pneumatic switch, and the silicone base are disposed in the cartridge; the cartridge comprises an e-liquid tank and an e-liquid inlet communicating with the e-liquid tank; the rotatable cover is adapted to cover the e-liquid inlet; the base sleeve is sheathed on the cartridge; the cartridge comprises a joint pin adapted to connect to the mouthpiece; the seal ring is sheathed on the joint pin of the cartridge; the silicone seal is disposed on the cartridge; the rotatable cover is rotatably disposed on the cartridge and covers the silicone seal.