The invention discloses a tension leg platform model mooring device which comprises a foundation support and a tension leg. The foundation support is fixed to the sea floor. An opening cavity is formed in the foundation support. A rotating sphere is arranged in the opening cavity. The outer surface of the rotating sphere and the inner wall of the opening cavity are connected with each other through multiple bearing steel balls. The tension leg comprises multiple tension leg single bodies. The end portions of every two adjacent tension leg single bodies are connected through elastic connecting pieces, the lower end of the lowest tension leg single body is connected with the rotating sphere, and the higher end of the highest tension leg single body is connected with an external platform model body. The device is not restricted by the traditional tension leg deflection angle any more, and then the more accurate testing result is obtained. Meanwhile, bearing of each tension leg single body is more uniform, and the problems that a traditional tension leg structure bears too heavy loads and the requirement for materials is high are optimized.