The research on the mechanism of bulge bag in non-PVC three-layer co-extrusion composite film solution container was carried out in this paper, which indicates that bulge bag under high temperature is caused by the gas outside the bag entering the inner side.It describes the impact of bulge on infusion bag products.The air volume in container as function of temperature and time was observed as well.The effects of temperature, time, humidity and pressure on bulge bag were analyzed via the L27 (34) orthogonal experimentThe results show that temperature contributes the most to the issue under exptl. conditions, followed by time, humidity and pressure.Suggestions are offered to resolve the bulge bag issues.