The adhesive strength of the laminated zipper bag composite substrate refers to the adhesive force per unit area of the substrate adhesive layer, which is used to measure the bearing capacity of the adhesive layer to external forces. 1. The factors that affect the adhesive strength include: the physical and chemical properties of the base material and flexible packaging composite base material, especially the surface microstructure and flatness of the base material, chemical structure composition and other factors that directly affect the adhesive strength. 2. Adhesives: various performance indicators of adhesives (fluidity, wettability, curing bonding ability) also affect the bonding strength. 3. The residual stress on the bonding surface of the zipper bag and the residual stress on the interface of the zipper bag composite are caused by the thermal stress caused by the different expansion coefficients between the base materials or between the base materials and the adhesive, and the chemical stress caused by their shrinkage during the curing process. 4. The thickness of the adhesive layer of the zipper bag. Generally speaking, in a certain thickness range, the peel strength increases with the increase of the thickness of the bonding layer, while the tensile and shear strength decreases. 5. Surface treatment of zipper bag substrate