Cavitation bubbles exist in diesel droplets when bulk liquids break up under supercavitation of diesel injection, and they can increase droplet instability during bubble growth, while the mechanism of this effect is still not clear. Spherically symmetric bubble expansion within diesel droplets was numerically simulated based on the volume of fluid (VOF) method, and the control mechanism and affecting factors of bubble growth were analyzed by Rayleigh-Plesset equation. The results show that the bubble growth process can be divided into three stages including surface tension controlled domain, comprehensive competition controlled domain and inertial force controlled domain. Cavitation bubble growth is mainly controlled by surface tension during the first stage, and the inertial force acting on bubble-liquid interface and the viscous force are insignificant. During the second stage, bubble growth is controlled by comprehensive competition among surface tension, inertial force and viscous force. Finally, bubble growth is significantly controlled by inertial force during the third stage. The effects of surface tension coefficient, liquid viscosity and density on bubble growth process were analyzed.%在超空化燃油射流使得喷雾中部分燃油分裂液滴内含有空化气泡；空化气泡的生长对液滴的分裂与雾化具有重要的影响。研究基于VOF方法对燃油液滴内空化气泡的生长过程进行了数值模拟，结合R-P方程对单液滴内空化气泡生长控制机理及影响因素进行了分析。结果表明，单液滴内空化气泡的生长可以按控制机理划分为表面张力控制阶段、综合竞争阶段和惯性力控制阶段。在第I生长阶段，空泡的生长主要受表面张力的控制作用；在第II生长阶段，空泡的生长主要受表面张力、惯性力及黏性力三者的综合作用；在第III生长阶段，空泡的生长主要受惯性力的控制作用。最后，利用建立的数值计算模型对表面张力系数、液体黏度及液体密度对液滴内气泡生长过程的影响进行了分析。
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