Composite drainage network is a new type of drainage geotextile. Made from high-density polyethylene (HDPE) as raw material and processed through a special extrusion molding process, it has a three-layer special structure. The middle reinforcement has high rigidity and is arranged longitudinally to form a drainage channel. The cross arranged reinforcement forms a support to prevent the geotextile from embedding into the drainage channel, and can maintain high drainage performance even under high loads.