Abstract: A new pseudo three-dimension (P3D) hydraulic fracturing model is built up by modifying the original single dimension fluid field with the local radial fluid field. To validate the rationality of the local radial fluid flow assumption, the fluid field in the fracture was studied by solving the coplanar potential fluid flow with FEM. Distribution of streamlines and the flow rate in the vertical direction are obtained. The distribution is well consistent with that obtained from the local fluid flow assumption, which effectively shows that the modified P3D model has greatly improved the original model. As the fluid flow and pressure drop in the vertical direction are taken into account, the fracture height as predicted by the modified model is much closer to the true value than that predicted by the original model for inadequately contained fractures.