Soft, thin, skin-integrated electronics, i.e. epidermal electronics, has become a hotspot in biomedical engineering and drawn great attention for their applications in health monitoring, disease diagnosis and therapies. However, soft powering system is still a challenge for epidermal electronics, since the thickness and weight of the existing flexible energy harvesting and storage devices are very hard to meet the requirements of epidermal electronics. Here we present a stretchable and flexible self-powering epidermal electronic device based on rubbery piezoelectric composites formed by a ternary blend of PDMS, lead zirconate titanate (PZT) and graphene. The mixed PZT rubber is soft, ultra-thin and light weight and intrinsically stretchable. By combining soft PDMS substrate and advanced mechanics designed interdigital electrodes/interconnects, a stretchable and skin-integrated device for tactile sensing is realized. The soft device can not only accurately measure a board range of force from 2.84 kPa to 11.72 kPa but also exhibit great flexibility that can maintain stable performance under various mechanical deformations, such as bending, stretching and twisting. On-skin demonstration tests reveal that this self-powering device can clearly distinguish the differences among mechanical stimulations such as touching, poking, tapping and hitting. Furthermore, the self-powering nature of these devices allows energy to be harvested from daily body actives, for instance, hard touching by hand can lighten up to 15 light-emitting diodes.