Couple of DOF technique in FEM and the algorithm for equation group solution in the whole stiffness matrix is studied in this paper. A new procedure is developed for the analysis of telescope beam structure. This method can solve most of the complex structural problems in engineering practice. This method has been used in the FEM analysis of pile frame of multifunction drilling machine, which is designed and manufactured by our research group. The right analysis result can improves the design efficiency and the reliability of the structure and reduce the design cost.