The detection of methane (CH 4 ) is an important issue in many fields. Typically, CH 4 is one of the most typical gases that effectively reflects the early latent pitfalls of the power transformer, the on-line monitoring of its concentration could effectively evaluate the operating status of the transformer, and prevent grid safety issues. However, current commonly used chemiresistive gas sensors are difficult to detect low-concentration of CH 4 at room temperature. Herein, we prepared a 3D MoS 2 /carbon nanofiber (CNF) network sensor via electrospinning and the followed thermal treatment. This sensor exhibited an unanticipated good response to CH 4 at room temperature, including high sensibility (5.82% towards 250 ppm), low limit of detection (10 ppm) and good stability (50% retention rate in 30 days). This study provides a general solution for preparing room-temperature chemiresistive CH 4 sensors and can be extended to other gas detection.