In recent years, flexible biomedical sensors have received extensive attention and achieved great development. However, the battery life of flexible biomedical sensors is limited, which has become a bottleneck restricting the development of flexible biomedical sensors. The concept of self-powered flexible biomedical sensor provides an important idea for solving battery life problem. This review summarizes the research progress of self-powered flexible biomedical sensors over the years. Besides, this review discusses several self-powered flexible biomedical sensors based on different power generation technologies and different materials, as well as their respective advantages and scope of application. Further, some representative research works are selected and discussed in detail. Self-powered flexible biomedical sensors can be divided into wearable self-powered flexible biomedical sensors and implantable self-powered flexible biomedical sensors according to their working positions, which can be used to collect important physiological indicators such as human respiration, pulse, temperature, etc. Finally, this paper also predicts and evaluates the future research direction of self-powered flexible biomedical sensors.