During tumor progression, the mechanical properties of the tumor microenvironment play a pivotal regulatory role. As core mechanical indicators, cellular stiffness and extracellular matrix stiffness profoundly influence tumor development through multiple pathways, including cytoskeletal remodeling, activation of signaling pathways, and metabolic regulation. Studies have demonstrated that the tissue stiffness of various solid tumors is significantly higher than that of corresponding normal tissues, while their cellular stiffness exhibits the opposite trend. This mechanical characteristic is also observed in oral squamous cell carcinoma and exerts crucial regulatory effects during tumor progression. This review systematically summarizes the molecular composition and regulatory mechanisms underlying the stiffness of tumor cells and extracellular matrix (ECM). Mainstream stiffness detection technologies such as atomic force microscopy, microfluidic deformation, and real-time deformability cytometry are outlined, with particular emphasis on their applications and limitations in oncology research. This review comprehensively analyzes how mechanical properties regulate key processes in tumor progression, including growth, proliferation, invasion, metastasis, angiogenesis, lymphangiogenesis, drug resistance, and immune escape. This review synthesizes biomechanics-based therapeutic strategies, including: ① targeting the regulation of tumor cell stiffness through cytoskeletal modulators and cholesterol-depleting agents to enhance immune responses; ② reducing ECM stiffness by matrix remodeling enzyme inhibitors, ECM component modulators, or receptor antagonists to improve drug delivery efficiency, and combining with immunotherapy or photothermal therapy for enhanced therapeutic effects; ③ enhancing the mechanical adaptability and anti-tumor activity of immune cells through pharmacological or genetic approaches. This review establishes a robust conceptual framework for developing novel anti-tumor therapeutic strategies and provides insights for future clinical management of oral squamous cell carcinoma.