In order to further improve the control performance of the power plant boiler combustion system, based on the analysis of the dynamic characteristics and influencing factors of a subcritical boiler combustion system, a new combustion system optimization design has been presented, the method got the fuzzy adaptive PID controller which can timely adjust the controller parameters as the main controller of each circuit adopts, in addition, according to the principle of feedforward compensation, the method also added a similar feedforward decoupling fuzzy controller between the coupling circuits. The MATLAB simulation result shows that the proposed double fuzzy control strategy compared with the conventional fuzzy adaptive PID control, response time shortened by 45.2%, overshoot amount was reduced by 53.6%, the regulating time reduced by 32.7%, enhanced the robustness, the control performance was greatly improved.