The article analyses the vibration of a high-power dual three-phase generator with eccentricity fault. Firstly, analyses the radial electromagnetic force decomposition and time-space dimension decomposition of the dual three-phase generator under different eccentricity conditions. Combined with the analytical expression of the radial electromagnetic force wave, the spatial and temporal order effects on the radial electromagnetic force are analyzed under different forms of rotor eccentricity. Then import the inhomogeneous electromagnetic force into the harmonic response module, simulate the electromagnetic vibration under the rotor eccentricity and analyze the effects of different rotor eccentricity forms on the generator vibration. The results indicate that eccentricity can cause harmonics in the time or spatial dimensions of the radial electromagnetic forces. Both static and dynamic rotor eccentricity lead to an increase in electromagnetic vibration of the generator. As the eccentricity distance increases, the vibration displacement of the generator also increases. Compared to the normal non-eccentric condition, additional vibration frequency components are observed.