Fruit knife capable of adjusting stretching/withdrawing of blades

The invention discloses a fruit knife capable of adjusting stretching/withdrawing of blades. The fruit knife is integrally formed by a handle and a knife head, wherein an angle is formed between the knife head and the handle to form an L shape; the fruit knife is provided with three blades in total; a first blade for peeling a fruit is mounted in a plane of the knife head; a second blade for cutting off the fruit peel and the first blade are mounted at the joint between the handle and the plane in a perpendicular mode; a button is fixed at the upper end of the second blade; a reset spring is arranged between the button and the handle; a third blade is arranged in a relatively large section of the handle in a folding manner; the knife head is a plane; the inside of the plane is a containing room; the upper part of the plane is provided with a knife groove; the first blade is mounted in the knife groove; the lower surface of the first blade corresponds to the containing room of the plane; a screw rod is rotatably mounted in the containing room in a direction vertical to the first blade; a nut is fixed below the first blade; and when the screw rod is rotated, the nut drives the first blade to move in the plane so as to adjust the stretching/withdrawing amount of the first blade.