A Hybrid Eulerian-Lagrangian method is employed to study a unsteady propagation flame thrush an air/fuel-droplet mixture in a one-dimensional closed constant volume combustor. The gas phase properties are obtained by using a continuum approach, whereas computation of liquid phase properties are based on a Lagrangian approach. A mixture air and fuel is ignited by providing a hot wall at end of the combustor. Following ignition, a flame initiates and propagates into the cold spray mixture. The characteristics of the propagating spray flame are presented in terms of profiles of gas phase and liquid phase properties. The effects of initial droplet size, fuel mass fraction are studied, Flame propagation rates and pressure rise rates seem to increase as fuel mass fraction increase, and droplet size decrease.