Abstract: The shock wave and turbulent boundary layer interaction induced by flat-faced blunt fin mounted on a flat plate is numerically studied. The calculation results display "A" shock wave structure generated by the impingement of separated shock with the bow shock. Some new phenomena are discovered in this flow through the simulation, such as the bifurcation and mergence of vortices in the separation region ahead of blunt fin, the existence of secondary separation and secondary vortex, multiple vortices structur...