A miniature methane sensor and a methane detection method are suitable for methane detection and are further suitable for methane detection of underground coal mine. The methane sensor comprises a heating component and one or more of measurement components, wherein the heating component is separately heated to a high-temperature working state, and the measurement component independent to the heating component does not apply an external current or voltage and is used for directly measuring the voltage so as to detect gas concentration. A methane sensor processing technology is compatible with aCMOS process. The methane sensor has the advantages of simple structure, low power consumption, high sensitivity, good interference resistance and low cost.