The optimal proportion of blending content among fluorogypsum,fly ash and cement of fly ash-fluorogypsum-cement composite binder(FFC binder) was known through the study.The experimental results show that FFC binder's dry shrinkage will decrease with the increase of the blending content of fluorogypsum,and FFC binder's soundness is good.The strength of fly ash-phosphogypsum-cement composite binder(FPC binder) is lower than that of FFC binder if the blending content of cement and fly ash in them is equal to each other.