Abstract: To help power grid absorb intermittent renewable energy generation, once-through boiler coal fired units are required to be operated in a wide load range, and meanwhile superheated steam temperature should be maintained stable. However, various disturbances and system nonlinearity can reduce load tracking rate and control performance of superheated steam temperature during varying load operation. Therefore, this study proposes an anti-disturbance control method of boiler-turbine coordinated system coupled with superheated steam temperature regulation. In this method, a dynamic model of the system is adopted to construct nonlinear control algorithm, and the high order sliding mode observer is used to estimate various disturbances in system. Simulation results reveal that compared with traditional proportional integral, two-degree-of-freedom proportional integral and linear active disturbance rejection control methods, the max absolute errors of system outputs decrease by more than 90%. Therefore, the designed method enables once-through boiler coal fired units to track load command rapidly and reject various disturbances effectively, while simultaneously maintaining superheated steam temperature stable so as to ensure safe and economic operation of the units.