Abstract: Sub-structure transfer matrix is often used to analyze the natural characteristics of multi-rotor systems. But, it is not easy to develop a versatile program for the transfer matrix because of its complexity in calculation and diversity of structures. A calculation procedure is thus given to integrate all the state vectors of individual rotors together so as to form a systematical state vector to link all rotors together through coupling elements. In this way no unknown internal force and displacement will be introduced in and no balance equations or conditions to coordinate different deformations are required at division points. Derives the transfer matrix of isotropic coupling element with some examples given to verify it, and results showed that the integrated transfer matrix is higher in computational accuracy and available to keep such advantages of conventional transfer matrix as easy to program, small workload and high operating speed. Thus, it provides an effective way to develop a versatile program.