The utility model relates to a dual power supply device applied to a lightning detection station in a remote area. The dual power supply device comprises a city power supply module and a solar photovoltaic power supply module. The city power supply module provides high voltage alternating current. The high voltage alternating current is reduced to low voltage alternating current through a step-down transformer. The low voltage alternating current is successively connected in series with a rectifier bridge and a filter capacitor to acquire a low voltage direct current power supply. The low voltage direct current power supply is connected in series with a first diode, and then is connected with a lightning monitoring device. The solar photovoltaic power supply module comprises a photovoltaic voltage output end. The photovoltaic voltage output end is connected with a hysteresis comparison control circuit. The hysteresis comparison control circuit is connected with a second diode, and then is connected with the lightning monitoring device. The dual power supply device provided by the utility model has the advantages of low cost, reasonable design, simple structure, reliable operation and being maintenance-free.