Disclosed is an inflatable airbag with an inflation channel free of a heat mark, comprising two cavity films (3), boundaries of the two cavity films (3) being closed to form a bag body, and further comprising two valve films (4) arranged between the two cavity films (3); the upper ends of the two valve films (4) are closed to form an inflation channel (1), and the lower ends are inserted into the bag body to form an air inlet (6); the bag body and the valve films (4) are separated into a plurality of small cavities (2) by hot pressing; the two valve films (4) are coated with heat resisting layers (5) at closed portions of the cavity films (3), and the heat resisting layers (5) are arranged between the two valve films (4); and an inflation opening (8) is formed in the inflation channel (1). The inflatable airbag is simple in structure, and low in costs and rejection rate, and compared with the prior art, the processing procedure of a hot sealing area is reduced, the production efficiency is greatly increased, and a wide market prospect is achieved.