The invention discloses a forming mechanism of a spring coiling machine, and relates to the technical field of spring coiling machines. The forming mechanism comprises a machine cabinet, a transverseadjusting plate is arranged outside the machine cabinet through transverse movement, and a transverse-moving control assembly is arranged between the machine cabinet and the transverse adjusting plate; the two ends of the transverse adjusting plate are each slidingly provided with a curve gauge base, and lifting control assemblies are arranged between the curve gauge bases and the transverse adjusting plate; deflecting curve cutter handles are arranged at one ends of the curve gauge bases, cutters are inserted into one ends of the curve cutter handles, and adjusting bolts penetrate through theends, away from the cutters, of the curve cutter handles through threads. The cutters can be adjusted in three-dimensional space, for steel wires with different diameters, the cutters can provide themost-stable support, and rebounding of springs during cutting can be effectively avoided. As the curve cutter handles independently move, the curve cutter handles can move to a best force bearing point according to shape changes of springs in the processing process, the processing stability is kept, springs with different sizes are thus processed, the processing accuracy is high, adjustment and controlling are easy and convenient, and the production efficiency and quality of springs are improved.