Abstract: An one-dimensional two-phase flow model is put forward for ignitron in solid propellant rocket,and its governing equations are derived. The gas pressure,tempera-ture,density and particle velocity in the ignitron are obtained from solution of the equations by finite difference method. A experimental apparatus has been set up to testify the calculations. From analyzing the results of the calculations and experiments the following conclusions are drawn. First, consistency of the flux calculated with the flux measured proves feasibility of the present calculation method;Second, the particle size and charge of igniter have significant effects on pressure in the ignitron; Third, the gas pressure,temperature and density in the burned area change very little, but the gas and particle velocities vary a lot; Last, the acceleration of flame spreading which comes from the calculations is testified in the experiments.