Abstract: The present invention relates to a device for forming a round bar into variable shapes, comprising: a main body provided with a plate portion with a circular shape having a plate hole formed in a center thereof, having plate protrusions protruding to the plate portion in a radial shape, and a turn gear connecting portion formed at an outer circumference surface of the plate portion; a round bar forming portion coupled between the plate protrusions and having a slide mold seated on the plate portion and a forming roll coupled to the slide mold to rotate; and a turn gear having a donut shape, provided with a turn gear protruding portion with a circular arc shape having different diameters from a center in an inner surface thereof, and disposed between the slide mold and the turn gear connecting portion.