The utility model discloses a multifunctional knapsack. Nine equal portions are drawn on the upper layer of a double-layer bed sheet to form equal 1/3 folding lines; straps are respectively arranged in the upward 20-40-cm positions at the left side and the right side of one block in the middle of the double-layer bed sheet; shoulder girdles and waist girdles with locking structures are respectively arranged above and below the straps; side strips with the width of 20-40 centimeters are respectively arranged on the folding lines in the upward 20-40-cm positions at the left side and the right side of the double-layer bed sheet and the folding lines above the double-layer bed sheet, and the side strips at the left side and the right side are 1-2 sandwich structures; the outer side edges of the sandwich structures and the lower ends of the transverse 1/3 folding lines are respectively provided with connecting zippers; both inner sides of the long side of each transverse 1/3 folding lines are respectively and uniformly provided with 68 button girdles for fixing connecting rods; and besides, the knapsack is provided with 4-12 vertical connecting rods, 6 transverse connecting rods, 6 ground connecting rods and 2-4 ground wheels. The multifunctional knapsack has simple and rapid operation and has multiple functions of a quilt, a knapsack, a hauling box, a sleeping bag bed, a stretcher, a stair and the like.