A switch control circuit of an electronic cigarette, comprising: a sensing circuit, comprising a first sensor, a second sensor and a heating part disposed between the first sensor and the second sensor for conveying heat to the first sensor and the second sensor; the first sensor is configured for detecting a first voltage generated by change of temperatures when an air flow is flowing over the first sensor; the second sensor is configured for detecting a second voltage generated by change of temperatures when the air flow is flowing over the second sensor; and a controller, coupled with a sensing circuit and stores a preset voltage threshold; the controller is configured for receiving the first voltage signal and the second voltage signal, comparing a voltage differential of the first voltage and the second voltage with the preset voltage threshold, and outputting corresponding action signals based on the comparison; wherein the voltage differentials and the atomizing powers have a positive correlation; if the voltage differential is greater, the atomizing power is greater; or variances of voltage differentials, and the atomizing powers have a positive correlation; if variances of voltage differentials are greater, the atomizing power is greater; characterized in that: wherein the action signals comprises: when the voltage differential is greater than zero and exceeding the preset voltage threshold, outputting a first signal for initiating the electronic cigarette; and when the voltage differential is less than the preset voltage threshold, outputting a second signal for closing the electronic cigarette. a sensing circuit, comprising a first sensor, a second sensor and a heating part disposed between the first sensor and the second sensor for conveying heat to the first sensor and the second sensor; the first sensor is configured for detecting a first voltage generated by change of temperatures when an air flow is flowing over the first sensor; the second sensor is configured for detecting a second voltage generated by change of temperatures when the air flow is flowing over the second sensor; and a controller, coupled with a sensing circuit and stores a preset voltage threshold; the controller is configured for receiving the first voltage signal and the second voltage signal, comparing a voltage differential of the first voltage and the second voltage with the preset voltage threshold, and outputting corresponding action signals based on the comparison; wherein the voltage differentials and the atomizing powers have a positive correlation; if the voltage differential is greater, the atomizing power is greater; or variances of voltage differentials, and the atomizing powers have a positive correlation; if variances of voltage differentials are greater, the atomizing power is greater; characterized in that: wherein the action signals comprises: when the voltage differential is greater than zero and exceeding the preset voltage threshold, outputting a first signal for initiating the electronic cigarette; and when the voltage differential is less than the preset voltage threshold, outputting a second signal for closing the electronic cigarette.