The integrated flow field implemented for variable flow ducted rocket. Compared with direct-connected ground test, the influence of air-fuel ratio on the performance and flow field of ducted rocket analyzed. The results show that the rocket thrust has been efficiently enhanced, together with specific impulse descending and range of missile reducing, by keeping missile flight state constant and reducing air-fuel ratio. While air-fuel ratio reduces to 7, the configuration of flow field in combustor changes, then a mass of fuel flows along the middle of combustor. The terminal shock wave of inlet moves toward the intake and the margin of inlet reduce by reduced air-fuel ratio.