The flow field in low pressure turbine guide vane was simulated by third order accuracy Godunov scheme with TVD property.The turbulence model was the combination of B-L algebraic model and MML model.A feature of this guide vane was existence of a long inlet duct with big meridional divergent angle in order to fulfill the requirements of the structure.The numerical simulation and analysis of the vortex structure in flow field indicated that a large separated zone resulted from the divergence of meridional profile.The separated zone not only increased loss before the stator but also increased the size and strength of horseshoe vortex and passage vortex.