Abstract: In this paper,circulating fluidized bed boiler(CFBB)ash is used as the main raw material for preparing baking free brick to obtain through experiment the optimal ingredients as follows:7%lime,43%fly ash,30% bottom ash,20%aggregate of oval stone.By steam curing and natural curing contrast,we find that the effect of nature curing is significantly lower than the steam curing.But with the increasing of lime dosage,the difference is gradually reduced.When lime dosage is higher than 7%,the test results are basically consistent.On this basis,unburned block labeled 150 can be produced using natural curing method through the expansion of industrial test.