The structural and mechanical properties of the needlepunched geosynthetic clay liner are analyzed by means of observing the surface morphology of the bentonite and carrying out tensile and peel tests. The study shows that the surface structure of the bentonite changes when water is encountered, which improves its impermeability; the woven film yarn geotextile provides the main tensile strength, which is 882.38N/10cm; the peel strength is below 100 N/10cm, which is far lower than the tensile strength; the bentonite layer before hydration has little effect on the mechanical properties; the MD strength of the geosynthetic clay liner after hydration is increased by 21.2% and the CD strength is increased by 11.8%, which proves that hydration has effect on the mechanical properties of the geosynthetic clay liner.