The utility model provides a prevent round -backed vest formula schoolbag, belongs to case and bag field, its characterized in that: the front and the schoolbag of back elastic webbing and waist elastic webbing are sewed up fixedly, the reverse side at the back elastic webbing is sewed up in the back thread gluing, the reverse side at the waist elastic webbing is sewed up in the waist thread gluing, back elastic webbing and waist elastic webbing pass through the back thread gluing and the waist thread gluing is connected with the vest, the back elastic webbing penetrates the shoulder of hole site in the vest, the back elastic webbing penetrates the hole through the back elastic webbing and penetrates the vest, wear to portal out the vest through the back elastic webbing, be connected through buckle and schoolbag, the waist elastic webbing penetrates the lower fourth department of hole site in the vest, the waist elastic webbing penetrates the hole through the waist elastic webbing andpenetrates the vest, waist elastic webbing end is fixed with the waist elastic webbing and connects the thread gluing. The utility model discloses an useful part lie in: the area of contact who has increaseed schoolbag and health in shoulder and waist position reduces pressure, has disperseed schoolbag weight.