For the 7-DOF heavy-duty hydraulic manipulator, an accurate and efficient inverse dynamic model of the heavy-duty hydraulic manipulator system was established. A manipulator dynamics model was established by using Newton-Euler recursion method, Spong flexible joint model and Stribeck friction model; Creo was used to complete the construction of the manipulator 3D model and it was imported to ADAMS to analyze and calculate. Compared with the test results, the determination coefficients are all greater than 0.6, which is significantly improved compared with the calculation results of the frictionless pure rigid body model. The accuracy of the modeling method is verified.