We propose a scheme for teleportation of an unknown three-atom W state without the Bell-state measurement. Firstly,we prepare an unknown three-atom W state by the resonant interaction between the atoms and the cavity. Then a quantum channel is prepared by sending two atoms through a single-mode cavity field,and driving them by a strong classical field at the same time. During the interaction between the atoms and the cavity,the states of these atoms are evolved. After the interaction,we prepare the EPR states,which form the quantum channel. Finally,we implement the teleportation of the unknown three-atom W state using the way of preparing the quantum channel. During the teleportation,the effects of thermal field and cavity decay are all eliminated. The success probability is 1.0.