Flexible electronic patches have been widely studied in various fields. However, they still face serious challenges in cardio-brain signaling monitoring to achieve accurate adhesion and detection with compatibility in mildly humid environments. To tackle these challenges, we engineered a gelatin hydrogel film cross-linked with a biocompatible matrix factor and combined it with a blend of liquid metal and PVP to create the flexible electronic patch. The flexible patch has good biocompatibility and fatigue resistance due to the incorporation of liquid metal and natural gelatin, with the conductivity of liquid metal and minimal toxicity of the gelatin film. It is possible to securely insert it into the body for a duration of 3 weeks while maintaining monitoring functionality and withstanding 10 000 cycles of flexural fatigue. This research provides an innovative approach to the future advancement of flexible electronic patches.