Abstract: The incremental harmonic balance nonlinear identification (IHBNID) is extended to high-dimensional nonlinear vibration system. The identification equation of multi-degree-of-freedom nonlinear dynamic system is derived. Numerical simulation on a two-degrees-of-freedom nonlinear system example, based on the IHBNID, was carried out on the period-1, the period-doubling and the chaotic motions. The effect of noise on the identification parameters is analyzed. The effectiveness of the IHBNID is verified for multi-degree-of-freedom nonlinear dynamic system. The simulating results show that the proposed method has high accuracy and efficiency, and can improve the antinoise ability.