An electronic cigarette, comprising: a mouthpiece assembly, the mouthpiece assembly A comprising a mouthpiece, a first seal ring adapted to seal the mouthpiece, a cylinder, a protective cover, a pin, and a slide block; an atomizing assembly, the atomizing assembly comprising a silicone seal, a silicone ring, a housing, a threaded connection ring, an atomization unit, a sealing element adapted to seal the atomization unit, a second seal ring adapted to seal the sealing element, a glass tube, and a third seal ring adapted to seal an upper part of the glass tube; and a base assembly, the base assembly comprising a fourth seal ring adapted to seal a lower part of the glass tube, a support adapted to support the glass tube, a vapor regulating ring, a base, a fifth seal ring adapted to seal the vapor regulating ring, a sixth seal ring adapted to seal the base, an insulation ring, and a joint; wherein: the mouthpiece assembly is disposed on the atomizing assembly; the atomizing assembly is disposed on the base assembly; the pin is mounted in the protective cover; the first seal ring is sheathed on the mouthpiece; the protective cover comprises a central hole and the cylinder is disposed in the central hole; the slide block is embedded in the protective cover; the mouthpiece is inserted in the cylinder; the protective cover is flexibly sheathed on the cylinder; the housing comprises a top surface towards the mouthpiece assembly, and the silicone seal and the silicone ring are disposed on the top surface; the second seal ring is sheathed on the sealing element, and the sealing element is disposed in the threaded connection ring; the atomization unit is screwed on the threaded connection ring; the threaded connection ring is inserted in the housing; the glass tube is disposed in the housing, and the third seal ring is embedded in the top surface of the housing; the top surface of the housing comprises a sliding rail and the slide block is disposed on the sliding rail; the slide block is limited on the top surface of the housing via the pin; the fourth seal ring is sheathed on the support to fix and seal the glass tube; the fifth seal ring and the sixth seal ring are disposed in the base; the vapor regulating ring is disposed on the base; a lower part of the support is embedded in the base; the insulation ring is sheathed on the joint, and the joint is disposed on the base. a mouthpiece assembly, the mouthpiece assembly A comprising a mouthpiece, a first seal ring adapted to seal the mouthpiece, a cylinder, a protective cover, a pin, and a slide block; an atomizing assembly, the atomizing assembly comprising a silicone seal, a silicone ring, a housing, a threaded connection ring, an atomization unit, a sealing element adapted to seal the atomization unit, a second seal ring adapted to seal the sealing element, a glass tube, and a third seal ring adapted to seal an upper part of the glass tube; and a base assembly, the base assembly comprising a fourth seal ring adapted to seal a lower part of the glass tube, a support adapted to support the glass tube, a vapor regulating ring, a base, a fifth seal ring adapted to seal the vapor regulating ring, a sixth seal ring adapted to seal the base, an insulation ring, and a joint; the mouthpiece assembly is disposed on the atomizing assembly; the atomizing assembly is disposed on the base assembly; the pin is mounted in the protective cover; the first seal ring is sheathed on the mouthpiece; the protective cover comprises a central hole and the cylinder is disposed in the central hole; the slide block is embedded in the protective cover; the mouthpiece is inserted in the cylinder; the protective cover is flexibly sheathed on the cylinder; the housing comprises a top surface towards the mouthpiece assembly, and the silicone seal and the silicone ring are disposed on the top surface; the second seal ring is sheathed on the sealing element, and the sealing element is disposed in the threaded connection ring; the atomization unit is screwed on the threaded connection ring; the threaded connection ring is inserted in the housing; the glass tube is disposed in the housing, and the third seal ring is embedded in the top surface of the housing; the top surface of the housing comprises a sliding rail and the slide block is disposed on the sliding rail; the slide block is limited on the top surface of the housing via the pin; the fourth seal ring is sheathed on the support to fix and seal the glass tube; the fifth seal ring and the sixth seal ring are disposed in the base; the vapor regulating ring is disposed on the base; a lower part of the support is embedded in the base; the insulation ring is sheathed on the joint, and the joint is disposed on the base.