A train parking heat insulation system based on a PLC is composed of a monitoring terminal, a train parking heat insulation control system and a train parking heat insulation system body.According to the train parking heat insulation system based on the PLC, a display terminal and the PLC industrial automation technology are combined, the communication capability is achieved, the diesel temperature, the lubricating oil temperature and the water temperature can be displayed in real time, the working states of a water pump, a diesel pump, a lubricating oil pump and heaters can also be detected, and the production working efficiency and safety are improved.The operating state of the train parking heat insulation system is monitored through a human-computer interface color touch screen.According to the water temperature, the lubricating oil temperature, the diesel temperature and other actual working conditions, a fuzzy controller is introduced to control the water pump, the diesel pump, the lubricating oil pump, the first heater and the second heater so that the temperature can be kept near to fixed values.