The invention discloses an automatic shirt folding device which comprises a rack, a folding part I, a folding part II, a folding part III, a folding part IV, a head support part and a PLC (Programmable Logic Controller), wherein the folding part I comprises a folding plate I, a folding plate bracket I, a folding guide rail support I, a guide rail and a sliding block capable of sliding on the guide rail; the folding part II comprises a front folding plate II, a rear folding plate II, two folding plate brackets II, a front guide rail support, a rear guide rail support, two guide rails and sliding blocks; the folding part III comprises a folding plate III, a folding part guide rail III, a tail box, a clamping plate, a tail press plate, a cylinder support, a sliding column and a tail box sliding block; the folding part IV comprises a folding plate IV and a folding plate bracket IV; the head support part comprises a head bracket, two L-shaped steel beams, a support plate bracket, a head press plate bracket, a head press plate and a support plate. To-be-folded clothes are placed on the support plate, the folding plates, the clamping plate and the tail press plate are driven to move by virtue of a cylinder so as to fold the clothes. The automatic shirt folding device is accurate and flat in folding, high in folding efficiency, high in speed, high in automation degree and low fabric blockage possibility.