This paper proposes a virtual-physical interaction based dynamic modeling method for improving the consistency between the constructed dynamic model (virtual) and the physical entity (physical) of gearbox. First, a dynamic model with initial parameters is built and applied to simulate the vibration signal. Second, the similarity between simulation and measured signals in the frequency domain is analyzed which can confirm the feasibility of the dynamic modeling method. Finally, the cosine similarity between simulation and measured signals in the time domain is calculated and selected as a criterion to update the dynamic model. Case study on a single stage gearbox has verified the effectiveness of the proposed method.