Coal mill outlet temperature control system and control method thereof

The invention provides a coal mill outlet temperature control system and a control method thereof, relates to the field of coal mill energy conservation and automatic control and solves the problem of boiler exhaust gas temperature rise. The system comprises a controller (1), a coal mill outlet temperature detector (2), a coal mill hot air adjusting door (3), a coal mill cold air adjusting door (4) and a coal mill capacity value detector (5), wherein the controller is respectively connected to the coal mill outlet temperature detector, the coal mill hot air adjusting door, the coal mill cold air adjusting door and the coal mill capacity value detector and used for receiving coal mill capacity values detected by the coal mill capacity value detector and coal mill outlet temperature detected by the coal mill outlet temperature detector and transmitting instructions for adjusting opening of the coal mill hot air adjusting door and the coal mill cold air adjusting door to control the coal mill outlet temperature.