For a syetem composed of a pair of V-type three-level atoms in entangled state and a pair of two-mode cavity fields in entangled state, a large detuning interaction between one atom with a cavity field is made to happen during a proper interaction time, so as to realize the entanglement between the atom and the cavity field. The atomic entropy evolution properties of the system are studied, and the influences of the detuning δ on the evolution of atom entropy are discussed by using the quantum entropy theory. The results indicate that δ affects the maximum entanglement value of the entropy and the collapse- recovery phenomenon of atom entropy, and when δ is zero, collapse-recovery phenomenon of atom entropy almost disappears.