The utility model discloses a storage battery bridging device of a direct-current power supply system. The utility model belongs to the technical field of power monitoring equipment. When the controlend of the single-chip microcomputer, namely an IO port, outputs a high level; the second resistor R2 and the third resistor R3 are connected in series for voltage division; at the moment, the base voltage of the first triode Q1 is lower than the emitter voltage; first triode Q1 conduction, by means of the enable circuit of the part, the load capacity of the control end of the single-chip microcomputer is improved. then, the base electrode of the second triode Q2 is electrified; second triode Q2 conduction, a coil of the relay KM is electrified; the enabling module and the switch module are driven together; the load capacity of the single-chip microcomputer can be improved, the controlled accuracy of the switch module is improved, it is guaranteed that a relay KM coil with large power canbe smoothly connected, no-delay bridging is achieved, uninterrupted power supply of a storage battery pack is guaranteed, power loss of a direct-current bus is effectively avoided, the situation thata protection device refuses to operate is effectively avoided, and the device is safer and more reliable.