对变速磨削系统稳定性进行了理论分析，通过坐标变换将变速磨削系统的变时滞微分方程转换为周期系数的常时滞微分方程。应用参数激励系统的Ｆｌｏｑｕｅｔ理论求得变速磨削系统的特征方程，并对变速磨削系统的稳定性图进行求解。结果表明，变速磨削能有效地提高磨削系统的稳定性。 The stability of variable speed grinding system is theoretically analyzed, and the variable delay differential equations of variable speed grinding system are transformed into the ordinary differential equations with periodic coefficients by coordinate transformation. Floquet theory of parameter excitation system was used to obtain the characteristic equation of variable speed grinding system and the stability diagram of variable speed grinding system was solved. The results show that variable speed grinding can effectively improve the stability of the grinding system.