To change the empty talk phenomenon of the research of a current AC servo system, virtual reality technology is used to develop the virtual simulation system of an AC servo system. This article described the fundamental principle of the sinusoidal pulse width modulation, introduced the functional structure of the virtual system. The fundamental principle of a wave display and the treatment of the key detail problems were solved. In the end, an example of the AC servo system simulation was given. The simulation of the AC servo system can be used as a soft device instead of a real one, and provide a technology platform for the development of a new AC servo system.