Direct-current power supply input end protector of airborne apparatus

A direct-current power supply input end protector of an airborne apparatus is used for improving the reliability of a switch power supply. According to the technical scheme, the protector comprises a transient inhibition diode, a power MOS tube, a boost strap boosted circuit and a feedback control circuit, the transient inhibition diode is connected with an output end of an input apparatus in parallel, the power MOS tube is connected between the input apparatus and a high frequency switch power supply in series, a grid of the power MOS tube is connected with output ends of the boost strap boosted circuit and the feedback control circuit. The utility model can adsorb the voltage peak, inhibit the starting-up surge current, clamp the over-voltage surge, and ensure the DC-DC high frequency switch power input end not to be interfered by the voltage peak, the input voltage and the starting-up surge current are all in the allowable range, and the DC-DC high frequency switch power supply can be ensured to work safely and reliably.