Mechanotransduction is a biological process through which cells perceive mechanical signals from the microenvironment via mechanoreceptors and convert them into intracellular biochemical signals to regulate cellular behavior. In vital pulp preservation therapy, the directional differentiation of dental pulp stem cells (DPSCs) is a critical step for the regeneration of the pulp-dentin complex. Recent studies have shown that mechanical signals in the microenvironment can significantly regulate the odontogenic differentiation of DPSCs through mechanotransduction mechanisms. This article systematically elucidates the perception and transduction mechanisms of mechanical signals, analyzes the regulatory effects of these signals on the behavior of DPSCs, and summarizes the current deficiencies of pulp capping materials in active regulation, as well as the application prospects of bioactive materials designed based on mechanical signal regulation for promoting the functional regeneration of the pulp-dentin complex. Future research should focus on constructing material systems that integrate mechanical and biochemical regulation, shifting the design of pulp capping materials from passive coverage to active mechanical guidance, thereby providing new strategies for achieving structurally and functionally integrated vital pulp preservation.