The invention relates to an air sac with air leakage prevention self-locking one-way valves. The air sac comprises an air sac body and the one-way valves, wherein the air sac body is formed by a rectangular first film layer, a rectangular second film layer, a rectangular third film layer and a rectangular fourth film layer in turn from top to bottom through heat sealing; a second one-way valve which is arranged in a first cavity formed by the second film layer and the third film layer, and a first one-way valve on a fifth heat sealing line are used for inflating the air sac; meanwhile, the second film layer and the third film layer which are provided with the one-way valves are integrally covered and inflated by the first film layer and the fourth film layer, and the one-way valves which are arranged between the second film layer and the third film layer are pressed through air pressure in the first film layer and the fourth film layer, so that the one-way valves are prevented from leaking air after the second film layer and the third film layer are inflated. The air sac has a simple and reasonable structure and good sealing effect; and the air tightness of the air sac can be effectively improved, the effective utilization time of the inflated air sac is prolonged, the defect that the one-way valves of the conventional air sac have poor air tightness is overcome, and the air sac is suitable for industrial manufacturing.