The utility model relates to a multifunctional combined bag and belongs to the field of knapsacks. The multifunctional combined bag comprises at least two single bags, wherein the single bags are piled to form a bag body; single bags positioned on the uppermost lowest side of the bag body are respectively an upper bag body and a lower bag body; one side provided with large straps is a positive side; one ends of the large straps are arranged on the front side of the upper bag body, and the other ends of the large straps are arranged on the front side of the lower bag body; the adjacent single bags are movably connected through inserted buttons; the inserted buttons are arranged on two side faces of the bag body. According to the multifunctional combined bag, a detachable knapsack is formed through combination of single bags, each single bag can serve as a handbag, the bag is detached and combined according to different occasions, combination of functions of the knapsack and handbag is realized, and articles are conveniently carried.