The traditional transition models do not consider the intermittency of the disturbances in the transition region from the laminar to turbulent boundary layer, therefore they can not predict the transition process very well. The present paper considers the intermittency and develops an engineering transition model based on SST turbulence model, by introducing an intermittency factor and following Hassan’s idea of constructing the transition model. This model is applied to the numerical simulation of the axisymmetirc hypersonic flow around a sharp cone. The numerical results are in good agreement with the experimental data. It is shown that this model developed by the authors may be applied successfully to the engineering computation of the transition for the hypersonic aircrafts.