In conclusion, a set of high-accuracy global coupled PESs of X ̃ and B ̃ state of H₂O has been improved by adding more ab initio points in O+H₂ channel to the previous calculation data reported by Jiang et al. and fitting all points by the PIP-NN method. The structural, energetic and spectroscopic properties of PESs are in good agreement with experimental measurements. The quantum dynamical calculations were implemented by using a Chebyshev real wave packet method, and the total cross section is consistent with the latest experimental measurements. The branching ratio of hydrogen generation is very small, and the product H₂ mainly distributes at the vibrational ground state with only X ̃ and B ̃ states considered. While diverting the initial wave packet from Frank-Condon region to B ̃-D ̃ conical intersection, the calculated branching ratio of H₂ generation channel increases obviously, which indicates an important role of higher D ̃ state on the dynamics for O+H₂ channel. It should be pointed out that a more accurate dynamical characterization of the X ̃-B ̃-D ̃ three-state model as well as more experimental work will be helpful to better understand the production of O(1D)+H₂(X ̃¹~Σ_g⁺ ) from water photodissociation at different wavelengths.