Electrostatic equilibrium and electrostatic shielding are important knowledge points in electromagnetics. The key point is that there are a large number of free electrons in the conductor, which are form a new charge distribution under an external electric field. The resulting additional electric field offsets the external field and makes the electric field inside the conductor zero everywhere. Then, if the external electric field continues to increase, can electrostatic equilibrium and electrostatic shielding be realized all the time? Are there limits to electrostatic equilibrium and electrostatic shielding? This paper analyzes the process of electrostatic balance from the