Abstract: Although vortex shedding is a self excited unsteady flow phenomenon in turbomachinery blading with a blunt trailing edge,and the trailing edge of a compressor is not blunt,the phenomenon of vortex shedding is still thought to occur in a compressor blade row because of the viscosity and pressure gradient.The flow in the boundary layer is strongly affected by the adverse pressure gradients that tend to make the flow to separate,so there are a lot of vortices in the blade region.A numerical study has been carried out to simulate trailing edge vortex shedding of some kind of compressor cascade.A series of flow simulation are performed,and the structure of flow field and the mechanism of unsteady flow are investigated preliminarily.The numerical results indicated that the flow is strong unsteady flow,though the boundary conditions are steady.When incidence is big,the trailing edge vortex shedding is like Karman vortex shedding.The frequency of vortex shedding and the position of separation are affected by the incidence and Mach number.