Abstract: For simulating gas-particle flows with particle-particle collision,the second-order moment two-phase turbulence model is composed of a particle turbulence model superposed with the kinetic theory of inter-particle collision. Theoretically this is not well justified. Based on the concept of particle large-scale fluctuation due to turbulence and particle small-scale fluctuation due to particle-particle collision, a two-scale second-order moment two-phase turbulence model accounting for inter-particle collision was developed. The proposed model was used to simulate gas-particle channel flows. The simulation results were in agreement with the experimental results reported in references and were near to the results obtained by using the USM-Θmodel.The large-scale Reynolds stresses were found to be larger than the small-scale Reynolds stresses in each direction.