The invention discloses a power supply cable de-icing device and a power supply cable de-icing method. The power supply cable de-icing device comprises a vibrator, a temperature and humidity sensor, a communication module, a power supply module and a controller, wherein the vibrator is arranged at a junction of a power supply cable and a tower and can drive the power supply cable to generation vibration so as to remove water drops or ice drops on the power supply cable; the temperature and humidity sensor is used for detecting the temperature and the relative humidity of air; the communication module is used for receiving a remotely transmitted control instruction and remotely transmitted weather information so as to correct a measured value of the temperature and humidity sensor; and the controller controls the operating state of the vibrator through receiving and processing data transmitted by the temperature and humidity sensor and the communication module. The power supply cable de-icing device is simple in structure, and can control the start frequency and the time between two adjacent times of start of a vibration motor according to different temperature and humidity conditions, thereby avoiding damages imposed on the power supply cable by long-time vibration. Meanwhile, the power supply cable de-icing device removes the water drops or the ice drops on the power supply cable to the maximum degree within the shortest working time of the vibration motor.