Portable inflatable back cushion

The utility model relates to a seat back cushion, in particular to a portable inflatable back cushion, which adopts the technical scheme that the portable inflatable back cushion comprises a coating body and an elastic air bag, wherein the elastic air bag is arranged in a cavity of the coating body, the elastic air bag is provided with at least one inflation chamber, and each inflation chamber isprovided with an inflation valve and is connected with an external inflation mechanism; and the side part of the coating body is connected with a fixing band. According to the utility model, rapid connection and positioning with the seat backrest are facilitated; the supporting thickness and strength are adjusted by changing the amount of air in the elastic air bag, good back supporting is provided for a user, the device can meet the requirements of different users, the fitting degree between the back of the human body and the seat is effectively enhanced, the muscular tension caused by long-time sitting is relaxed, a