In order to explore the matching mechanism between nozzle throat area and afterburner fuel supply in turbofan engine afterburner process, and to find the technical way to improve the engine afterburner characteristics, the number of engine afterburner on and off process considering the dynamic volume effect of afterburner and external duct was established based on the afterburner fuel supply sequence, fuel filling sequence and tailpipe area regulation law of a turbofan engine The influence of nozzle throat area adjustment delay on the afterburner transition process is studied. The calculation example and result analysis show that: in the process of afterburner connection, the influence of nozzle delay adjustment on the fan stability margin and speed is not more than 4%, and the impact on the main engine stability margin and speed is not more than 1%; when the nozzle area adjustment is delayed or stuck, in order to ensure the main engine to work stably, the afterburner fuel supply can be appropriately reduced to improve the nozzle flow capacity and improve the safety and stability Under special circumstances, fuel supply of main combustion chamber should be increased to ensure afterburner thrust. The research results can provide reference for similar engine afterburner control law research, design and troubleshooting.