Abstract: Numerical simulations were carried out for a mixing enhancement measure-streamwise surge plus low velocity flow inlet-for specific supersonic mixing layer in dual combustor ramijet's(DCR's) supersonic combustor.The results show that,if streamwise surge is added at low velocity flow inlet,the positive impact on mixing enhancement is evident,and the burning intensity is increased,however it still belongs to weak combustion.The frequency determines the location and scale of vortices assembling region,and the swing determines uniform degree of distributed and assembled vortices.