本文理论上较全面地分析了空泡在水涡轮机械流场中的受力，考虑了很多文献被忽略的速度梯度场中的Ｓａｆｆｍａｎ升力，空泡旋转时的Ｍａｇｕｓ升力等力．利用牛顿第二定律建立了流场中空泡的质心运动方程，同时建立了空泡在变压场中以及考虑气体扩散的径向运动方程，最后导出了空泡在不可压缩流体中运动的控制微分方程。 This paper theoretically analyzes the force of cavitations in the flow field of water turbomachinery in a comprehensive way. Considering many literatures, the Saffman lift in the velocity gradient field and the Magus lift force when the cavitates rotate are considered. The equations of motion of the center of mass in the flow field are established by Newton ’s second law. At the same time, the radial equations of motion of the bubble in the transformer field and gas diffusion are established. Finally, the control differential of the movement of the bubble in the incompressible fluid equation.