Abstract: DES(detached eddy simulation) is a hybrid methodcombining RANS and LES to simulate flowfields with detached eddies. The mainidea is that, RANS is used near the wall and LES method is used in the otherregion of the field. In this paper, DES method based on M-SST was used tosimulate the complicate turbulence flows on hybrid unstructured grids andthe Osher scheme was used for the spatial discretisation. The computationsof the flow around a missile with a lateral jet was performed by using thenewly-developed codes. The obtained results demonstrate that DES method isefficient for some simulation of the separated turbulence flowfields.