By the method of coherent-state orthogonalization expansion, the energy spectrum of the V type three-level atom was calculated exactly in the non-rotating wave approximation, and a level-crossing problem was also considered by means of fidelity. The influences of the initial states of the V type three-level atom and the parameter of the binomial optical fields on the second-order coherence degree were studied. The numerical results indicate that: when the atom is initially in the ground state, the duration of the bunching effect increases at the beginning and then decreases with the increasing of η; when the atom is initially in the coherent state, the duration of the bunching effect decreases with the increasing of η. Finally, both cases of the light fields displayed anti-bunching effect completely when the value of η was large enough. When other parameters didnot change,the average of G2(t) increases with the enlargement of coupling strengh.