The 3D composite drainage network is made of high-density polyethylene (HDPE). The ribs are extruded through a special die. The three ribs are arranged according to a certain distance and angle to form a 3D spatial structure with drainage guide channel. The middle rib has greater rigidity, forming a rectangular drainage channel. The results show that the three-layer ribs of the drainage network have high longitudinal and transverse tensile strength and compressive strength,the drainage guide channel formed between the three-layer ribs is not easy to deform under high load, which can prevent the geotextile from embedding into the core of the geonet and ensure smooth drainage. The 3D geotechnical drainage network has high strength and high drainage type according to the requirements.