A packaging bag for shockproof comprising: a bottom wall, comprising a plurality of bottom air columns, the bottom wall further comprising two outer longitudinal heat sealing lines located on both sides of the bottom wall; a first shielding portion, comprising a plurality of first shielding air columns, wherein the first shielding portion and the bottom wall are integrally connected to an upper side of the bottom wall, the first shielding portion is folded above a surface of the bottom wall by a first folding line, both lateral sides of the first shielding portion are adhered to the surface of the bottom wall by means of heat sealing, and a first nesting space is formed between the first shielding portion and the bottom wall; a second shielding portion, comprising a plurality of second shielding air columns, wherein the second shielding portion and the bottom wall are integrally connected to a lower side of the bottom wall, the second shielding portion is folded above the surface of the bottom wall by a second folding line, both lateral sides of the second shielding portion are adhered to the surface of the bottom wall by means of heat sealing, and a second nesting space is formed between the second shielding portion and the bottom wall; and a limiting film, stacked above the bottom wall, comprising a body; characterized by the limiting film comprising further a reversed portion, located in the second nesting space, wherein the reversed portion is connected to a bottom end of the body and is folded on a top surface of the body by a folding line, the outer longitudinal heat sealing lines separately adhere the reversed portion, the body and an inner wall surface of the second shielding portion to the bottom wall, the reversed portion comprises two inner longitudinal heat sealing lines located between the outer longitudinal heat sealing lines, whereby the reversed portion is adhered to the inner wall surface of the second shielding portion, an accommodation space is formed between a bottom surface of the body, the surface of the bottom wall and the outer longitudinal heat sealing lines, and a limiting space is formed between the top surface of the body, an inner side of the reversed portion and the inner longitudinal heat sealing lines. a bottom wall, comprising a plurality of bottom air columns, the bottom wall further comprising two outer longitudinal heat sealing lines located on both sides of the bottom wall; a first shielding portion, comprising a plurality of first shielding air columns, wherein the first shielding portion and the bottom wall are integrally connected to an upper side of the bottom wall, the first shielding portion is folded above a surface of the bottom wall by a first folding line, both lateral sides of the first shielding portion are adhered to the surface of the bottom wall by means of heat sealing, and a first nesting space is formed between the first shielding portion and the bottom wall; a second shielding portion, comprising a plurality of second shielding air columns, wherein the second shielding portion and the bottom wall are integrally connected to a lower side of the bottom wall, the second shielding portion is folded above the surface of the bottom wall by a second folding line, both lateral sides of the second shielding portion are adhered to the surface of the bottom wall by means of heat sealing, and a second nesting space is formed between the second shielding portion and the bottom wall; and a limiting film, stacked above the bottom wall, comprising a body; characterized by the limiting film comprising further a reversed portion, located in the second nesting space, wherein the reversed portion is connected to a bottom end of the body and is folded on a top surface of the body by a folding line, the outer longitudinal heat sealing lines separately adhere the reversed portion, the body and an inner wall surface of the second shielding portion to the bottom wall, the reversed portion comprises two inner longitudinal heat sealing lines located between the outer longitudinal heat sealing lines, whereby the reversed portion is adhered to the inner wall surface of the second shielding portion, an accommodation space is formed between a bottom surface of the body, the surface of the bottom wall and the outer longitudinal heat sealing lines, and a limiting space is formed between the top surface of the body, an inner side of the reversed portion and the inner longitudinal heat sealing lines. a body; characterized by the limiting film comprising further a reversed portion, located in the second nesting space, wherein the reversed portion is connected to a bottom end of the body and is folded on a top surface of the body by a folding line, the outer longitudinal heat sealing lines separately adhere the reversed portion, the body and an inner wall surface of the second shielding portion to the bottom wall, the reversed portion comprises two inner longitudinal heat sealing lines located between the outer longitudinal heat sealing lines, whereby the reversed portion is adhered to the inner wall surface of the second shielding portion, an accommodation space is formed between a bottom surface of the body, the surface of the bottom wall and the outer longitudinal heat sealing lines, and a limiting space is formed between the top surface of the body, an inner side of the reversed portion and the inner longitudinal heat sealing lines.