The invention is related to an electronic cigarette and an assembly method therefor. The electronic cigarette comprises an electronic cigarette body and a mouthpiece device connected at one end of the electronic cigarette body. The electronic cigarette body is provided with at least one first smoke channel. The mouthpiece device is provided with a second smoke channel. The mouthpiece device is in a sliding butting connection with the electronic cigarette body. The junction between the mouthpiece device and the electronic cigarette body is provided with an elastic assembly. The elastic assembly is used to enable the first smoke channel and the second smoke channel to be in communication with one another or to be staggered from one another and not in communication. The beneficial effects of the electronic cigarette are that a child may be prevented from smoking the electronic cigarette by accident, and assembly is easy.