Micro heaters are widely used in the fields of gas sensors, gas galvanometers, infrared light sources, and collection of fine particles. Recently, micro heater for gas sensor usually use platinum as it's electrode material. This paper aims to improve the wearability of flexible gas sensors. Because graphene has high thermal conductivity, low convective heat coefficient, and good toughness, it has the potential to replace traditional metal materials to make electrode structures for flexible sensor components. In this paper, three simulation models of graphene-based micro heater are established, and the thermal performance of three micro heaters was compared and analyzed. COMSOL is applied to simulate and analyze thermal distribution of the models. Results show that, when the applied voltage is 9V, the steady-state temperature of the micro heater is between104-105 , and at this time the power consumption achieved 146 mW. The graphene-based micro heater can basically meet the needs of the optimal working temperature of flexible gas sensor. This work helps in the wearable development of flexible sensors.