HDPE geomembrane is currently widely used in garbage sanitary landfills and has strong durability. However, HDPE geomembrane has significant thermal expansion and contraction deformation, which is difficult to prevent. Therefore, during construction, it is necessary to reserve the deformation and expansion amount for thermal expansion and contraction to prevent damage to HDPE geomembrane. Moreover, the geotextile membrane is completed on the same day of laying, minimizing wrinkles and dragging as much as possible, otherwise excessive stress caused by local deformation may cause damage to the geotextile membrane.