AbstractWith the rapid technological development, self‐powered sensor systems that are capable of operating without an external power supply are becoming more and more crucial in the field of sensing and detection. One of the major drawbacks of a typical sensor is the necessity of an external power supply or batteries, which makes sensor systems more complex and less handy for mobile devices. In the last decade's improvement of triboelectric, piezoelectric, pyroelectric, and thermoelectric nanogenerators and their performance in electrical output and mechanical stability, it becomes widely used in the field of self‐power sensing systems for healthcare, mechanical and environmental applications. Here in this review, the various types of nanogenerators working principles is first discussed, the output performance is analyzed, and then their recent progress in the application of self‐powered sensor systems, including biomedical and healthcare, wearable devices, physical applications, robotics, environmental monitoring, and smart cities, is highlighted. Except for the practical application of self‐powered sensors, a future outlook of the self‐powered sensor systems is prognosticated.