Self-powered sensors are pivotal in sectors like space exploration, industrial monitoring, and particularly health surveillance, owing to their independence from external power sources. However, their energy utilization efficiency is hindered by complex energy conversion processes, leading to brief operational durations and significant data loss. Triboelectric nanogenerators (TENGs), capable of converting mechanical energy from friction into electricity, present a solution by enabling single-cycle sensing and transmission, thus promoting instantaneous wireless sensing. Addressing the size and transmission limitations in wearable technologies, we introduced an instantaneous self-powered wireless sensing system based on a TENG and a human body (HB-WTENG). This novel system utilizes the human body as a transmission antenna, converting TENG output into attenuated sinusoidal signals with encoded sensing information for real-time wireless communication. Demonstrated to support self-powered pressure sensing and signal transmission up to 8 m, the HB-WTENG offers a compact and deployable solution for continuous monitoring, marking a significant advancement in wearable sensor technology.