Since the combustion system of the Circulating Fluidized Bed Boiler (CFBB) is a complex object characterized by multiple variables, long time-delay, tight coupling, and time-varying. This paper introduces a new method of fuzzy decoupling, which fuzzy rules were used for compensation decoupling unit. And it puts forward for the strongly multivariable coupling of the combustion control system. From the simulation of the CFBB by using MATLAB/SIMULINK, the new method has effective decoupling performance, and it has good dynamic characteristic and static characteristic.