With nearly 20 years of improvement and development, dual fluoroscopic imaging system (DFIS) has become a proven technique for biomechanical study. This paper reviews the relevant literature and introduces the development history, main structure and function of DFIS. DFIS has been widely used in biomechanical study of knee joint with the advantages of non-invasive, precision and dynamic observation. Therefore, this paper also summarizes the application progress of DFIS in normal knee joint and knee joint postoperative biomechanical research, and looks forward to the possible research direction in the future.