Abstract：This paper derives a flexible model for the vertical axis automatic washing machine. First, a finite element model is established in ANSYS. Modal analysis is carried out and the result is proved by experiment. The modified Craig-Bampton modal is employed to derive a flexible model for the tub which is then coupled with the rigid model to establish a flexible model of the whole system. The generalized- method is used to solve the DAEs of the dynamic model, and the deformations and loads of the tub are obtained. At last, the loads are sent back into ANSYS for further analysis. The deformations calculated by ANAYS are compared with those obtained by our model and the effectiveness of the flexible model built in this paper is proved.