In the multielectronic states model, the dissociative behavior of H + 2 in intense laser field is calculated with the two order split propagator algorithm. It shows that for high frequency laser pulse H + 2 is multiphoton dissociated under the considered laser intensity and the momentum distribution of dissociative fragment is nearly symmetric. But for lower frequency laser pulse the molecule field interaction is dominated by tunneling dissociation and the momentum distribution of fragment H + is asymmetric. In addition, the effects of the laser pulse shape on the dissociation probability and the dissociation dynamics of H + 2 are discussed.