Triboelectric nanogenerator (TENG) manifests distinct advantages such as multiple structural selectivity, diverse selection of materials, environmental adaptability, low cost, and remarkable conversion efficiency, which becomes a promising technology for micro-nano energy harvesting and self-powered sensing. Tribo-dielectric materials are the fundamental and core components for high-performance TENGs. In particular, the charge generation, dissipation, storage, migration of the dielectrics and dynamic equilibrium behaviors determine the overall performance. Herein, we presented a comprehensive summary to elucidate the dielectric charge transport mechanism and tribo-dielectric material modification principle toward high-performance TENGs. We started with the contact electrification and charge transport mechanism of dielectric materials, followed by introducing the basic principle and dielectric materials of TENGs. Subsequently, modification mechanisms and strategies for high-performance tribo-dielectric materials were highlighted regarding physical/chemical, surface/bulk, dielectric coupling, and structure optimization. Furthermore, representative applications of dielectric materials based TENGs as power sources, self-powered sensors were demonstrated. The existing challenges and promising potential opportunities for advanced tribo-dielectric materials were outlined, guiding the design, fabrication, and applications of tibo-dielectric materials. This article is protected by copyright. All rights reserved.