The utility model provides a capacitive energy storage device, and belongs to the technical field of power charging and supplying. The capacitive energy storage device comprises a diode V32, a voltage stabilizing circuit, a current-limiting circuit and a diode V25 which are sequentially connected, wherein the current-limiting circuit is formed by a resistor R14 and a resistor R15 which are connected in parallel, a positive electrode of the diode V32 is connected with an external power supply, a negative electrode of the diode V32 is connected with the voltage stabilizing circuit, a positive electrode of the diode V25 is connected with the current-limiting circuit, and a negative electrode of the diode V25 is connected with a load circuit. The capacitive energy storage device further comprises an energy storage circuit formed by a plurality of energy storage unit circuits which are connected in series, wherein a positive electrode end of the energy storage circuit is connected with an anode of the diode V25, and a negative electrode end of the energy storage circuit is grounded. In a circuit device, the capacitive energy storage device can act as a standby power supply when the external power supply is interrupted, and has the characteristics of long service life, energy conservation, environment protection and the like. The circuit does not need a complex switching circuit, is short in switching time, and can ensure the device to have uninterrupted power supply when the external power supply is normal or interrupted in operation.