Numerical study of plug nozzle flow field and thrust characteristic was completed based on 3-D TLA NS equations with NND2M scheme. Calculations were performed under ideal, perfect gas assumptions. Turbulence was taken into account with a k-εturbulence model. The results show a significant performance increases at the sea level compared with the bell nozzle. They also show that NND2M scheme is fit for numerical simulation of complex jet flow.