Portable and flexible pressure sensors with highly sensitive and small size have great potential applications in areas such as wearable electronics, environmental monitoring, and medical equipment. Here, we demonstrate an integrated self-powered pressure sensing system made of a passive resistive pressure sensor and a triboelectric nanogenertor. Based on wrinkled and flexible polydimethylsiloxane films, the whole device is of sandwich structure with ultrahigh sensitivity to pressure ( ), which is more than one order of magnitude higher than all previously reported flexible pressure sensors. And our system exhibits a very low detection limit, rapid response time, and long-term stability. In addition, we built a self-powered, portable visualization system for semi-quantitative analysis of pressure, which can directly convert a pressure information to visual display.