An electronic cigarette, comprising: a mouthpiece subassembly; an e-liquid storage subassembly; an atomizing subassembly; and a base subassembly; wherein: the mouthpiece subassembly is mounted on the e-liquid storage subassembly; the atomizing subassembly is disposed in the e-liquid storage subassembly; the base subassembly is connected to the e-liquid storage subassembly; the mouthpiece subassembly comprises a cigarette holder, a fixed cover, a first seal ring, a first fixed ring, a decoration cover, a flexible cover, and a sliding part; the cigarette holder is inserted in the fixed cover; the first seal ring is disposed in the fixed cover to seal the cigarette holder; the first fixed ring is disposed outside the fixed cover to fix the flexible cover; the decoration cover is disposed on the flexible cover; the sliding part is disposed at a bottom of the flexible cover; the e-liquid storage subassembly comprises an e-liquid leakproof part, a silica fixed ring, a second fixed ring, a second seal ring, a glass tube, a hollow threaded column, and a third fixed ring; the e-liquid leakproof part and the silica fixed ring are fixed on the second fixed ring; the glass tube sleeves the hollow threaded column; the second seal ring is disposed in the second fixed ring to seal the glass tube; the second fixed ring is disposed on the hollow threaded column; the third fixed ring is screwed on the hollow threaded column to fix the glass tube; the second fixed ring comprises a groove which corresponds to the sliding part of the mouthpiece subassembly; the e-liquid storage subassembly is connected to the mouthpiece subassembly via the cooperation of the sliding part and the second fixed ring; the atomizing subassembly comprises a limit cover, a heating wire support, an insulation ring, and an electrode; the electrode is embedded in the insulation ring; the insulation ring is disposed in the heating wire support; the heating wire support is disposed in the limit cover; the atomizing subassembly is disposed in the hollow threaded column; and the base subassembly comprises a joint, a protective part of the joint, a vapor adjusting ring, a fourth fixed ring, a third seal ring, a fourth seal ring, and a base; the base subassembly is connected to the atomizing subassembly via the joint; the protective part and the joint are sequentially disposed in the base; the vapor adjusting ring is fixed on the fourth fixed ring; the third seal ring seals the base, and the fourth seal ring seals the vapor adjusting ring; the fourth seal ring, the fourth fixed ring, and the third seal ring are sequentially disposed on the base; the vapor adjusting ring is screwed on the base; the base is screwed on the hollow threaded column of the e-liquid storage subassembly. a mouthpiece subassembly; an e-liquid storage subassembly; an atomizing subassembly; and a base subassembly; the mouthpiece subassembly is mounted on the e-liquid storage subassembly; the atomizing subassembly is disposed in the e-liquid storage subassembly; the base subassembly is connected to the e-liquid storage subassembly; the mouthpiece subassembly comprises a cigarette holder, a fixed cover, a first seal ring, a first fixed ring, a decoration cover, a flexible cover, and a sliding part; the cigarette holder is inserted in the fixed cover; the first seal ring is disposed in the fixed cover to seal the cigarette holder; the first fixed ring is disposed outside the fixed cover to fix the flexible cover; the decoration cover is disposed on the flexible cover; the sliding part is disposed at a bottom of the flexible cover; the e-liquid storage subassembly comprises an e-liquid leakproof part, a silica fixed ring, a second fixed ring, a second seal ring, a glass tube, a hollow threaded column, and a third fixed ring; the e-liquid leakproof part and the silica fixed ring are fixed on the second fixed ring; the glass tube sleeves the hollow threaded column; the second seal ring is disposed in the second fixed ring to seal the glass tube; the second fixed ring is disposed on the hollow threaded column; the third fixed ring is screwed on the hollow threaded column to fix the glass tube; the second fixed ring comprises a groove which corresponds to the sliding part of the mouthpiece subassembly; the e-liquid storage subassembly is connected to the mouthpiece subassembly via the cooperation of the sliding part and the second fixed ring; the atomizing subassembly comprises a limit cover, a heating wire support, an insulation ring, and an electrode; the electrode is embedded in the insulation ring; the insulation ring is disposed in the heating wire support; the heating wire support is disposed in the limit cover; the atomizing subassembly is disposed in the hollow threaded column; and the base subassembly comprises a joint, a protective part of the joint, a vapor adjusting ring, a fourth fixed ring, a third seal ring, a fourth seal ring, and a base; the base subassembly is connected to the atomizing subassembly via the joint; the protective part and the joint are sequentially disposed in the base; the vapor adjusting ring is fixed on the fourth fixed ring; the third seal ring seals the base, and the fourth seal ring seals the vapor adjusting ring; the fourth seal ring, the fourth fixed ring, and the third seal ring are sequentially disposed on the base; the vapor adjusting ring is screwed on the base; the base is screwed on the hollow threaded column of the e-liquid storage subassembly.