A study quantifies the interfacial triboelectricity in inorganic-organic composite mechanoluminescent (ML) materials, revealing its critical role in determining ML intensity. The research establishes a positive correlation between the difference in triboelectric series and ML intensity, achieving a 20-fold increase in ML intensity by selecting an appropriate inorganic-organic combination. The interfacial triboelectricity-regulated ML is demonstrated in multi-interface systems, including inorganic phosphor-organic matrix and organic matrix-force applicator interfaces, and confirmed by self-oxidation and reduction of emission centers under continuous mechanical stimulus. The findings provide direct experimental evidence for the ML mechanism and guidelines for designing high-efficiency ML materials. The study also explores self-oxidation and self-reduction induced by electron transfer in ML, showing that the ML intensity of inorganic-organic composites is positively correlated with the triboelectric charge and relative triboelectric series difference. The results demonstrate that the number of triboelectric charges at the interfaces of phosphors and the organic matrix is the key factor to determine the ML intensity in inorganic-organic composites. The study provides a new perspective on the mechano-to-photon conversion mechanism and the design principle of self-recoverable ML materials, which could promote the development of ML for advanced sensing, self-powered lighting, and biomechanical engineering applications.A study quantifies the interfacial triboelectricity in inorganic-organic composite mechanoluminescent (ML) materials, revealing its critical role in determining ML intensity. The research establishes a positive correlation between the difference in triboelectric series and ML intensity, achieving a 20-fold increase in ML intensity by selecting an appropriate inorganic-organic combination. The interfacial triboelectricity-regulated ML is demonstrated in multi-interface systems, including inorganic phosphor-organic matrix and organic matrix-force applicator interfaces, and confirmed by self-oxidation and reduction of emission centers under continuous mechanical stimulus. The findings provide direct experimental evidence for the ML mechanism and guidelines for designing high-efficiency ML materials. The study also explores self-oxidation and self-reduction induced by electron transfer in ML, showing that the ML intensity of inorganic-organic composites is positively correlated with the triboelectric charge and relative triboelectric series difference. The results demonstrate that the number of triboelectric charges at the interfaces of phosphors and the organic matrix is the key factor to determine the ML intensity in inorganic-organic composites. The study provides a new perspective on the mechano-to-photon conversion mechanism and the design principle of self-recoverable ML materials, which could promote the development of ML for advanced sensing, self-powered lighting, and biomechanical engineering applications.