利用平衡稳定性判据和静电场的高斯定理证明了仅受静电力作用的点电荷不可能处于稳定平衡状态，分析了其适用条件，并给出了相应的教学建议．

By applying the condition for stability of equilibrium and Gausss law, it is proved that any point charge cannot be held in stable equilibrium by electrostatic forces alone; the scope of application is emphasized, and corresponding teaching suggestions are put forward.