The invention discloses a secondary reheat unit monitoring system. The secondary reheat unit monitoring system comprises a boiler body subsystem, a boiler flue gas subsystem, a turbine-side secondaryreheat subsystem and a controlling center; the boiler body subsystem comprises a boiler wall temperature part and a boiler steam-water system part, the boiler wall temperature part comprises a plurality of temperature measuring points, and the boiler steam-water system part comprises a plurality of temperature measuring points and pressure measuring points; the boiler flue gas subsystem comprisesa plurality of temperature measuring points, pressure measuring points, air volume measuring points and oxygen quantity measuring points; the turbine-side secondary reheat subsystem comprises a plurality of temperature measuring points, pressure measuring points and a liquid level switch; and the controlling center is used for receiving, processing, storing and displaying detection data of the measuring points and controlling operation of corresponding mechanisms of the secondary reheat units. According to the secondary reheat unit monitoring system, a basis can be provided for regulating thetemperature, pressure, flow quantity, oxygen quantity, air volume and the like of the secondary reheat unit through a multi-point multi-position measuring point arrangement, and safety operation requirements of the secondary reheat units are met.