The present invention relates to an temperature control system of an e-cigarette, which includes a power supply, a liquid guiding member, and a heating element, and further includes an operating voltage input unit separately connected to the power supply and the heating element, a temperature detection unit including a voltage detection module and a temperature processing module that are connected to each other, and an operating voltage adjusting unit separately connected to the temperature processing module and the heating element. According to the present invention, a temperature of the heating element is controlled by using the temperature control system. This avoids the following problems: When the e-cigarette operates, because the temperature of the heating element increases with a longer operating time, the liquid guiding member is burnt or e-liquid molecules are cracked to produce a burnt taste, thereby affecting human health as well as smoke taste and user experience.