Processing method for fan duct

The invention relates to a processing method, wherein a spinning lathe is comprised. The processing method is characterized in that an expanding die is arranged on a telescopic chuck on a main shaft of the lathe; a duct blank part is sleeved on the expanding die, and the telescopic chuck is propped by the tail top of the lathe so as to tension the expanding die; a horn mouth profiling wheel and a spinning wheel cling to the front end face of the duct blank part and respectively cling to the external wall and the internal wall of the duct blank part; a flange side overturning wheel and the spinning wheel cling to the rear end face of the duct blank part and respectively cling to the internal wall and the external wall of the duct blank part; the lathe can be started spin for a time to achieve the spinning work of the horn mouth profiling wheel and a flange overturning side. The processing method is simple in technology, saves welding and has high material utilization rate and low cost of production, is easy to