Abstract: In terms of the complex dynamic characteristics and mass imbalance phenomenon of a dual-rotor system, a dynamic model of the internal and external dual-rotor system was established. Its vibration characteristics were analyzed through axis trajectory diagram, time-domain diagram, spectrum diagram, Poincaré cross-section diagram and bifurcation diagram, and a dual-rotor experimental platform was built to conduct the acceleration and imbalance experiments and verify the correctness of theoretical research and computer simulation. Results show that during the acceleration process of the dual-rotor, there will be two sudden increases in amplitude, and the two main resonances are caused by the internal and external rotor speeds reaching the natural frequency of the system respectively. The dual-rotor system exhibits different vibration characteristics at different speeds. Increasing the imbalance of the internal rotor not only affects the vibration response of the internal rotor system, but also affects the vibration response of the external rotor system, and the impact on the former is more significant.