Biological systems perceive and respond to mechanical forces, generating mechanical cues to regulate life processes. Analyzing biomechanical forces has profound significance for understanding biological functions. Therefore, a series of molecular mechanical techniques have been developed, mainly including single-molecule force spectroscopy, traction force microscopy, and molecular tension sensor systems, which provide indispensable tools for advancing the field of mechanobiology. DNA molecules with a programmable structure and well-defined mechanical characteristics have attached much attention in molecular tension sensors as sensing elements, and have been designed for the study of biomechanical forces to present biomechanical information with high sensitivity and resolution. In this review, we will present a comprehensive overview of molecular mechanical technology, with a particular focus on molecular tension sensor systems, specifically those based on DNA. Finally, we look forward to the future development and challenges of DNA-based molecular tension sensor systems.