The invention relates to the field of sweatpants and discloses a production device of sweatpants. The device comprises a cotton core wood pulp material frame, a cotton core crushing and forming mechanism, a cotton-core-coated non-
woven fabric material frame, a flow guiding layer material frame, a cotton core cutter, a
crotch lifting
rubber band material frame, a PE bottom
film material frame, a surface-layer non-
woven fabric material frame, an encircling
rubber band material frame, an encircling non-
woven fabric material frame, a core body cutter, a core body
vertical transfer wheel, a speed-variable transverse change mechanism, a core body transverse transfer wheel, a
waistline rubber band material frame, a
waistline non-woven fabric material frame, a rear O-shaped cutter, folding conveying part, a corset conveying part and an
ear folding mechanism which are arranged in sequence. An inner-layer non-woven fabric material frame, an arc-shaped rubber band material frame, an
abdomen rubber band material frame, an outer-layer non-woven fabric material frame and an arc-shaped rubber band applying mechanism are sequentially arranged between the speed-variable transverse change mechanismand the core body transverse transfer wheel; a front cutter and a bifurcator are sequentially arranged between the arc-shaped rubber band applying mechanism and the core body transverse transfer wheel. The device can realize production switching between two-piece sweatpants and three-piece sweatpants and is reasonable in design.