The invention discloses a control method of a three-phase photovoltaic energy storage system of an electrified railway. Operation states of a traction power supply system and a photovoltaic power generation system are detected in real time, and charging/discharging power of the energy storage system is dynamically distributed; peak shaving and load shifting are carried out on photovoltaic energy, and self generation and self utilization of the photovoltaic energy are realized; light abandoning and power limitation are carried out on a photovoltaic system under an extreme condition, and a condition that power is conveyed back to a power system by the traction power supply system after photovoltaic switching-in is avoided, so that safe and stable operation of the traction power supply system is not influenced by the photovoltaic switching-in. According to the control method, the consumption capability of the photovoltaic energy can be remarkably improved; meanwhile, the condition that the power is conveyed back to the power system by the traction power supply system is avoided, so that the problem that three-phase power flows possibly have different directions when three phases of an energy-storage-free photovoltaic power generation system are switched into the traction power supply system is radically solved.