Abstract: The boiler combustion control system is one of the main control systems of the thermal power plant unit. It has the characteristics of large delay，variable load，multi- disturbance and nonlinearity. The variables have coupling relationship. Therefore，it is difficult to establish an accurate control model. To this end，a new decoupling method was proposed，which introduced decoupling parameters to realize decoupling control of the system. The combustion control system was simulated in the Matlab environment. The simulation results show that the control precision of the system is greatly improved.

Key words: combustion control system, coupling, decoupling