In order to study the stability of the pile-anchor retaining structure, based on the limit analysis upper bound theory, taking the pile body and its surrounding fill as a whole, considering the influence of factors such as soil delamination, cohesion, anchor cable tension and the friction between the fill and the pile body and the pile bottom, a theoretical model of the stability of the pile-anchor retaining structure is established, and the formula for calculating the stability coefficient of the pile-anchor retaining structure is derived and verify the reasonableness of the method by relevant engineering examples. In addition, the influence of anchoring force F, pile diameter D, and the lengthe bedded section H2 on the stability coefficient Fs of pile anchor retaining structure was discussed. The results show that the stability coefficient of pile anchor support structure increases with the increase of anchoring force, pile diameter, and the length embedded section, among which the embedded section length has a significant impact on the stability coefficient, which can provide reference for relevant engineering examples.