The invention relates to a device and a method for controlling a solar air conditioner. The device for controlling the solar air conditioner comprises an indoor solar air conditioner control device, an outdoor solar air conditioner control device, an outdoor power supply circuit, an
indoor outdoor communication circuit and an outdoor communication circuit. The indoor solar air conditioner control device and the outdoor solar air conditioner control device respectively comprises a solar air conditioner
control function unit, a shared energy-storage
capacitor, a solar DC-DC boosting, isolating and exchanging device and a
solar battery; the outdoor power supply circuit comprises a power switch, an EMC circuit and an outdoor DC high-
voltage power supply which are respectively connected with the commercial power network; the outdoor DC high-
voltage power supply, the output of the solar DC-DC boosting, isolating and exchanging device, the DC high-
voltage power supply input of the indoor solar air conditioner control device and the DC high-voltage power supply input of the outdoor solar air conditioner control device are all directly connected with the shared energy-storage
capacitor in parallel; the
solar battery is connected with the solar DC-DC boosting, isolating and exchanging device; and the solar DC-DC boosting, isolating and exchanging device is connected with the indoor solar air conditioner control device and the outdoor solar air conditioner control device by the
indoor outdoor communication circuit and the outdoor communication circuit.