A pressure-relieving backpack, wherein, the pressure-relieving backpack comprises: a backpack body, a pressure-relieving plate, a pressure-relieving assembly, two shoulder straps, and a supporting plate for supporting the backpack body; the supporting plate is provided at a rear portion of the backpack body, the pressure-relieving plate is provided at a side of the rear portion of the backpack body near back; the pressure-relieving assembly comprises a spring mechanism and a hollow casing; the casing is mounted at the rear portion of the backpack body, and the spring mechanism is detachably provided inside the casing; the spring mechanism comprises a compression spring and a retractable rod, the compression spring is sleeved around and position-limited with respect to the retractable rod; the casing and the retractable rod both have a first end and a second end; the second end of the retractable rod and the compression spring are position-limited within the casing, the first end of the retractable rod is located outside the casing and can be extended and retracted upward and downward relative to the first end of the casing; the first end of the retractable rod is detachably connected to a lower end of the pressure-relieving plate, an upper end of the pressure-relieving plate is connected to upper ends of the shoulder straps, and lower ends of the shoulder straps are connected to a lower end of a back side of the backpack body; characterized in that the casing comprises two clamps, an inner wall of each of the clamps protrudes outwardly to form a slideway, two slideways are oppositely disposed, and the retractable rod is located in a chamber formed by the two slideways and can be extended and contracted upward and downward; wherein the two clamps are respectively referred to as a first clamp and a second clamp, the first clamp is fixedly mounted on the rear portion of the backpack body, the slideway of the first clamp faces away from the backpack body, and the second clamp is detachably mounted on the first clamp. the pressure-relieving assembly comprises a spring mechanism and a hollow casing; the casing is mounted at the rear portion of the backpack body, and the spring mechanism is detachably provided inside the casing; the spring mechanism comprises a compression spring and a retractable rod, the compression spring is sleeved around and position-limited with respect to the retractable rod; the casing and the retractable rod both have a first end and a second end; the second end of the retractable rod and the compression spring are position-limited within the casing, the first end of the retractable rod is located outside the casing and can be extended and retracted upward and downward relative to the first end of the casing; the first end of the retractable rod is detachably connected to a lower end of the pressure-relieving plate, an upper end of the pressure-relieving plate is connected to upper ends of the shoulder straps, and lower ends of the shoulder straps are connected to a lower end of a back side of the backpack body; characterized in that the casing comprises two clamps, an inner wall of each of the clamps protrudes outwardly to form a slideway, two slideways are oppositely disposed, and the retractable rod is located in a chamber formed by the two slideways and can be extended and contracted upward and downward; wherein the two clamps are respectively referred to as a first clamp and a second clamp, the first clamp is fixedly mounted on the rear portion of the backpack body, the slideway of the first clamp faces away from the backpack body, and the second clamp is detachably mounted on the first clamp.