Abstract: A two-fluid model was applied to simulate compressible two-phase flow in JPL(Jet Propulsion Laboratory) nozzle and supersonic jet two-phase flow.And,the interactional mechanism of gas phase and particle phase,rules of particles flowing at different sizes were studied.Program "Solve2D" solving two-dimensional axisymmetric compressible two-fluid model with body-fitted coordinate system was developed.The program was used to solve gas phase Navier-Stokes(N-S) equations with k-ε turbulence model.For particle phase,Euler equations were solved.Two phases were coupled through source terms.Gas-particle two-phase flow field of JPL nozzle and jet were studied under different particle mass percentages and different particle sizes.