Flexible and wearable sensors play a pivotal role in shaping advances in smart medical devices. However, the practicality and economy of current wearable flexible sensing devices have seriously hindered their wide application. Here, relying on the electrospinning method, material modification and triboelectric nanogenerator technology, we present a novel highly sensitive flexible triboelectric nanogenerator (TENG) sensor with the characteristics of flexible and sensitive. Through meticulous exploration of the exceptional triboelectric properties of polyvinylidene fluoride nanofiber and a rigorous investigation into the corresponding preparation processes, we have achieved remarkable results. The TENG created using positively polarized polyvinylidene fluoride nanofiber outperforms TENG created with electrospun polyvinylidene fluoride nanofibers, delivering output performance several times higher. Additionally, our fabricated highly sensitive flexible TENG sensor demonstrates exceptional sensitivity, achieving a response time of just 4 ms under controlled laboratory conditions—a notable improvement over previous iterations. Importantly, leveraging the excellent electrical output characteristics of TENG, we can generate a self-powered morse code producer system and the human motion sensor, which is demonstrates its wide application in the field of smart medical devices. Therefore, our research offers a groundbreaking avenue for developing high-output TENG and presents a pivotal solution for the design of innovative TENG applications.