A power distribution priority controller of a photovoltaic power generation system, comprising: a calculating unit configured to calculate an electric device priority list according to running state information of electric devices and photovoltaic power generation data and to determine a preferred power distribution schemes; a controlling unit configured to acquire in real time the running state information of all electric devices, and control the electric devices according to the preferred power distribution schemes determined by the calculating unit; a communicating unit configured to transmit the photovoltaic power generation data, the running state information of the electric devices, and control command information; and a storage unit configured to store, in time units, the photovoltaic power generation data, the running state information of the electric devices, and the preferred power distribution schemes; characterised in that the electric device priority list is calculated according to the equation below, and the preferred power distribution scheme is determined according to priorities in a descending order: PRI = 1 T ∑ n = 0 T T 1 t d + p d P s + σ wherein PRI denotes the power distribution priority of an electric device, and the smaller the PRI value is, the higher the priority of the electric device is; T denotes a sampling period; T 1 denotes a reference time for determining a priority; t d is the duration of using the electric device within T 1 time in the T period every day; p d is the maximum power of the electric device; p s is the maximum power supply of the current photovoltaic power generation system; σ is a time priority coefficient, within the T 1 time period, the closer the time of using the electric device is to a current time, the smaller the σ is. a calculating unit configured to calculate an electric device priority list according to running state information of electric devices and photovoltaic power generation data and to determine a preferred power distribution schemes; a controlling unit configured to acquire in real time the running state information of all electric devices, and control the electric devices according to the preferred power distribution schemes determined by the calculating unit; a communicating unit configured to transmit the photovoltaic power generation data, the running state information of the electric devices, and control command information; and a storage unit configured to store, in time units, the photovoltaic power generation data, the running state information of the electric devices, and the preferred power distribution schemes; characterised in that the electric device priority list is calculated according to the equation below, and the preferred power distribution scheme is determined according to priorities in a descending order: PRI = 1 T ∑ n = 0 T T 1 t d + p d P s + σ wherein PRI denotes the power distribution priority of an electric device, and the smaller the PRI value is, the higher the priority of the electric device is; T denotes a sampling period; T 1 denotes a reference time for determining a priority; t d is the duration of using the electric device within T 1 time in the T period every day; p d is the maximum power of the electric device; p s is the maximum power supply of the current photovoltaic power generation system; σ is a time priority coefficient, within the T 1 time period, the closer the time of using the electric device is to a current time, the smaller the σ is. wherein PRI denotes the power distribution priority of an electric device, and the smaller the PRI value is, the higher the priority of the electric device is; T denotes a sampling period; T 1 denotes a reference time for determining a priority; t d is the duration of using the electric device within T 1 time in the T period every day; p d is the maximum power of the electric device; p s is the maximum power supply of the current photovoltaic power generation system; σ is a time priority coefficient, within the T 1 time period, the closer the time of using the electric device is to a current time, the smaller the σ is.