The invention discloses an emergency power source box and an operation method thereof. The emergency power source box comprises a charging module, a storage battery module, a rectification and inversion module and a large capacitance module; the charging module converts AC 220V into a charging voltage of a storage battery and charges the storage battery; the storage battery module is formed by connecting two lead acid batteries in the 12V DC voltages in series; the rectification and inversion module inverts the 24V DC voltage into an AC 24V via a bridge, and boosts the AC 24V into AC 220V by astep-up transformer after filtering, and converts the AC 220V into DC 220V by a rectifier bridge; and the large capacitance module stores instant electric energy, and provides a sufficient instant motion current for motion of a permanent magnetism switch. The power supply box is low in weight, simple in operation, safe and efficient, enables normal operation of power lines, ensures the stabilityof a power system, and avoids the frequent condition that closing cannot be carried out due to insufficient power of a controller in practical production.