Aiming at a 440t/h CFB boiler of Lianzhou power plant,an optimal combustion experiment was preceeded.This paper analyzed the effect of oxygen content in flue gas,the secondary air rate,the load, adding limestone into the CFB boiler on flue gas heat loss,unburned carbon loss and boiler efficiency,the cause of high attemperation water flow is discussed.Measures for improving the combustion efficiency and reasonable opearation parameters that can be a reference for the operating of the same type CFB boiler are...