A buffering inflatable packaging bag comprising a containing part and an isolating part that are composed of an inflatable plastic capsule; the inflatable plastic capsule has a plurality of bar-shaped inflatable chambers, each of which communicates with an overall passage of gas inflation via a one-way check valve; wherein: - the containing part is provided with a containing cavity adapted to carry a contained article; the containing cavity is a folded portion of the inflatable plastic capsule along a length direction of the bar-shaped inflatable chamber by means of two first thermally sealing lines comprising a short thermally sealing line that lies on each of the bar-shaped inflatable chambers in the middle of the inflatable plastic capsule and is less than a width of the bar-shaped inflatable chamber in length, said folded portion being sealed along a first sealing line provided on both sides of the inflatable plastic capsule; an opening of the containing cavity is an opening of the containing part; - the isolating part is a double-layer structure having a first and a second layers, the isolating part being formed by folding the inflatable plastic capsule along the length direction of the bar-shaped inflatable chamber by means of two third thermally sealing lines each comprising a short thermally sealing line that lies on each of the bar-shaped inflatable chamber in the middle of the inflatable plastic capsule and is less than the width of the bar-shaped inflatable chamber in length, both sides of said isolating part being sealed by a second sealing line provided on both sides of the inflatable plastic capsule; - a second thermally sealing line is provided at a joint of the isolating part and the containing part along a width direction of the bar-shaped inflatable chamber, said the second thermally sealing line comprising a short thermally sealing line that lies on each of the bar-shaped inflatable chambers in the middle of the inflatable plastic capsule and is less than the width of the bar-shaped inflatable chamber in length, one end of the double-layer structure being provided at one side of the opening of the containing part; the first layer being connected with the opening of the containing part on one side; - the first layer being shorter than the second layer of the double-layer structure, the second layer being adapted to provide support for the first layer and to withstand a surface of a contained article in the containing cavity. - the containing part is provided with a containing cavity adapted to carry a contained article; the containing cavity is a folded portion of the inflatable plastic capsule along a length direction of the bar-shaped inflatable chamber by means of two first thermally sealing lines comprising a short thermally sealing line that lies on each of the bar-shaped inflatable chambers in the middle of the inflatable plastic capsule and is less than a width of the bar-shaped inflatable chamber in length, said folded portion being sealed along a first sealing line provided on both sides of the inflatable plastic capsule; an opening of the containing cavity is an opening of the containing part; - the isolating part is a double-layer structure having a first and a second layers, the isolating part being formed by folding the inflatable plastic capsule along the length direction of the bar-shaped inflatable chamber by means of two third thermally sealing lines each comprising a short thermally sealing line that lies on each of the bar-shaped inflatable chamber in the middle of the inflatable plastic capsule and is less than the width of the bar-shaped inflatable chamber in length, both sides of said isolating part being sealed by a second sealing line provided on both sides of the inflatable plastic capsule; - a second thermally sealing line is provided at a joint of the isolating part and the containing part along a width direction of the bar-shaped inflatable chamber, said the second thermally sealing line comprising a short thermally sealing line that lies on each of the bar-shaped inflatable chambers in the middle of the inflatable plastic capsule and is less than the width of the bar-shaped inflatable chamber in length, one end of the double-layer structure being provided at one side of the opening of the containing part; the first layer being connected with the opening of the containing part on one side; - the first layer being shorter than the second layer of the double-layer structure, the second layer being adapted to provide support for the first layer and to withstand a surface of a contained article in the containing cavity.