Flexible thermoelectric generators (FTEGs) can continuously harvest energy from the environment or the human body to supply wearable electronic devices, which should be a clean energy solution and provide an opportunity to satisfy the increasing power consumption of multimodal sensing and data transmission in wearable electronic devices. Here, the 64-pair FTEG was fabricated by introducing the plated through-hole and heterotypic electrode structures to optimize the thermal transport, showing the largely improved output power of 4.1 mW and record-high power density of 312 μW cm