Abstract: Based on commercial CFD software Fluent，numerical simulations for flow field of co-axial jet stream in a Texaco gasifier cold test bed was investigated with the Spalart-Allmaras（S-A）turbulence model，standard k-ε（S k-ε）model，RNG k-ε model，Realizable k-ε（R k-ε）model and RSM turbulence model respectively.The sensibility to grid quality，grid style and boundary types of these models were discussed.The accuracy and performance of these five turbulence models were evaluated according to the comparison of simulation results and cold test results.The S-A model and standard k-ε model had better compatibility with grid quality and type but poor simulation results.The RSM model had a too rigorous limitation of grid quality to predict velocity field correctly，while the RNG k-ε model and Realizable k-ε model had better numerical solution based on a reasonable grid.