The invention discloses a thermal power plant 0 class load power supply system and control method. The system comprises an energy storage device, an AC uninterrupted power load low-voltage power distribution device, an AC security load low-voltage power distribution device, and a DC security load DC power distribution device. The AC uninterrupted power load low-voltage power distribution device, the AC security load low-voltage power distribution device and the DC security load DC power distribution device are internally provided with an AC uninterrupted power load bus, an AC security load busand a DC security load bus respectively. The energy storage device is connected to the AC uninterrupted power load bus, the AC security load bus and the DC security load bus through a first switch, asecond switch and a third switch. The AC uninterrupted power load bus is also connected to a first power supply for a thermal power plant power through a fourth switch, and the AC security load bus is also connected to a second power supply for the thermal power plant power through a fifth switch. The system is intensively streamlined, compared with a conventional method, fully static equipment improves the reliability of a 0 class load power supply of the thermal power plant, the power supply quality is improved, and pollutant emissions are reduced.