Engineering accidents often occur due to the anchorage force loss of prestressed anchor cables leading to anchorage failure. There is a complex coupling effect relationship between the anchorage force loss of anchor cables and the creep of rock and soil mass. Through theoretical analysis and model research, a coupling effect calculation model based on strain equality is established on the basis of the common rheological model of rock and soil mass, and the model is verified. The coupling effect model between the two is established, and the calculation relationship between the two is established, which provides the theoretical basis and technical means for the design, construction, safe operation management and the control and compensation technology of the anchoring force loss of the prestressed anchorage engineering.