Abstract: PEDF system has the advantages of green and low carbon, peak shaving and valley filling, and high energy efficiency, which will become an important development direction of building power distribution. PEDF system supplies power to the DC air conditioner through the DC bus voltage, the rectifier filter circuit and power factor correction circuit are saved, the cost of air conditioner is reduced. However, when changes in photovoltaic output, load switching, and other factors cause power imbalance within the system, significant fluctuations in the DC bus voltage pose a challenge to the stable operation of DC air conditioning motors.the topology of the PEDF system and the DC air conditioning drive system are analyzed, and the control strategy of PEDF system based on maximum power tracking and double closed-loop control is studied. A motor control strategy combining SMO, MTPA and leading angle flux weakening is adopted to deal with the DC power supply voltage fluctuation. By introducing DC bus voltage as a control variable, the control parameters of the motor are quickly adjusted, achieving stable motor speed. Especially when the motor is running at high speed and heavy load, the leading angle flux weakening can quickly adjust the motor’s quadrature-and direct-axis currents, preventing the stator current from exceeding the limit value and achieving stable operation of the air conditioner in the full speed range under DC bus voltage fluctuations. The PEDF system including DC air-conditioning motor is built in Matlab/Simulink software. The simulation is carried out according to the actual air-conditioning operating conditions, and the effectiveness of the proposed control strategy is verified.