The present application provides a method and a device for generating smoking signals in electronic cigarettes and an electronic cigarette using the method and the device. The method includes these steps: using airflow passing through a vocal cavity of an electronic cigarette to drive the vocal cavity to vibrate and generate an ultrasonic wave; using an acoustic-electric conversion unit mounted on the vocal cavity to convert the ultrasonic wave into a voltage signal; and using a microprocessor of the electronic cigarette to generate a control signal according to the voltage signal and start a heating and atomizing process of tobacco juice in the electronic cigarette.