Auto-gating power supply is the energy source of low light level image intensifiers, and research on its local bright-light protection method is of great significance for improving the control strategy of auto-gating power supply and the bright-light performance of low light level image intensifiers. This paper analyzes the advantages and disadvantages of the low light level image intensifier that matches the DC high-voltage power supply and auto-gating power supply in the application of a large dynamic illumination range. A design idea for an auto-gating power supply is presented, which can provide the low light level image intensifier with high illumination application and low illumination local bright-light protection and offers a control strategy for an auto-gating power supply circuit.