In order to control the combustion field reasonably， it is necessary to analyze the atomization quality in the combustion chamber and the ignition delay period of the propellant during the efficient propulsion of the liquid rocket. The three-dimensional atomization combustion field model is using the ICEM module， and the atomization characteristics of centrifugal nozzle under different conditions are analyzed by DPM discrete phase model. The EDC combustion model is coupled to analyze the combustion development process and ignition delay characteristics of n-decane， n-octane and aviation kerosene. The results show that with the increase of nozzle pressure， the penetration distance of droplets increases while D32 decreases.. When the nozzle diameter increases from 1.2 mm to 1.8 mm， the axial velocity of the droplet decreases and the atomization angle increases. With the increase of back pressure， the collision and aggregation effect between droplets is obviously enhanced， and the aerodynamic effect is weakened， resulting in the increase of D₃₂. The length of ignition delay period in the combustion field is positively correlated with the ambient temperature and back pressure.