An analytical procedure of gas-particle mixture flow in the De Laval nozzle is described for the case where the curved convergent part of nozzle has been prescribed. The effect of particle volume fraction, particle clouds, and nozzle configuration on the gas-particle flow is analytically considered. According to the Mach numbercheckout method, the critical cross-sectional area of the nozzle and the behavior of the supersonic gas-particle flow were determined and calculated respectively.