In the era of advanced wearable electronic devices, the triboelectric nanogenerators (TENGs) as energy harvesting and self-powered sensing units hold great promise. Selecting appropriate triboelectric material is the crucial factor to optimize the performance of TENG, while polytetrafluoroethylene (PTFE) stands out as a highly versatile option among the various materials. In this study, we present an ultrafine nanofibrous PTFE (NF-PTFE) films prepared by novel in-situ fibrillation strategy as the triboelectric material in TENG devices. The innovative processing methodology facilely addresses the dilemma between high porosity and fine pore size of traditional porous PTFE films, meanwhile achieves exceptional mechanical strength, hydrophobicity, air permeability, and chemical resistance of the films. With the integration of nanofibrous PTFE films into contact-separation mode TENG and droplet-based TENG, these devices realize the peak electrical output of 131 V/10.8 μA and 54 V/14 μA with great durability, which surpass the performance of TENGs using traditional expanded PTFE films. Furthermore, a smart glove capable of recognizing hand gestures is proposed, which demonstrates the versatility, flexibility, and practicality of this material for potential use in smart devices. This reported NF-PTFE film provides insights for the design of high-performance TENG device for advanced wearable electrical applications.