Abstract: PATL foil has a thinner aluminium coating,and is of high resilience,when used as an inner liner,the foil tends to be creased or torn in the folding process in GDX2 packer,which may result in machine failures.Therefore,the packer was modified by altering the related folding parts,precisely setting the clearances between the moving folding parts,and the foil was folded with the combination of moving folding and fixed folding.The moving folding device was responsible for forming dead fold lines,then completed the folding procedures by fixed folding device.The results of experiments showed that:the machine shutdown caused by liner folding was basically avoided,the liner changing time for a packer shortened by 3.6 hours per month,the machine efficiency increased by 10%.