An error compensation method based on assembly constraints of aircraft pipe is proposed for solving the problem of frequent failures caused by high assembly stress in the actual assembly process. Firstly， the pipe assembly process’ geometric modeling is carried out using geometric modeling method， and a new modeling method based on axis vector is proposed. On this basis， the Rodrigues formula is used to establish a pipe space pose calculation model based on actual assembly conditions. Then， the assembly constraints are analyzed， and the key constraint features are identified based on the pipe assembly requirements. Subsequently， the pipe assembly scenarios under different constraint forms are analyzed， and the pipe error compensation methods under a single constraint and associated constraint are respectively proposed. Finally， a typical flaring pipe is selected for the test； the pipe assembly error compensation calculation and the pipe installation air tightness test are carried out， respectively. The results show that the proposed method could effectively realize the theoretical space pose adjustment and the pipe parameter compensation， and the air tightness of the compensated pipe is better than that of the uncompensated one.