The water retention and drainage board is a lightweight panel made from high-density polyethylene (HDPE) or polypropylene (PP), which is shaped through heating and pressure to create a drainage channel that provides a certain level of spatial support rigidity while also retaining water. This type of panel integrates both water retention and drainage functions. It features extremely high spatial rigidity and significantly better compressive strength compared to similar products (which can be verified through on-site testing). It can withstand high compressive loads exceeding 400Kpa and can also endure high loads during the mechanical compaction of backfill soil on the planting roof. It functions to create internal drainage layers, discharge infiltrated water from the soil, and store part of the infiltrated water. Compared to the previous generation of drainage products, it has the following advantages and disadvantages: 1. In the northern regions with little rainfall and aridity, the water retention and drainage board can store water, which is beneficial for plant growth. The side walls of the board's protrusions are relatively thick, allowing for high compressive strength, capable of reaching over 40 tons, which is significantly greater than similar products like plastic protrusions (high-density polyethylene drainage boards, high-impact polypropylene drainage boards) and plastic drainage mats (which can be verified through actual compaction tests). It meets the construction requirements during backfilling and normal operational demands. 2. The water retention and drainage board has a relatively large supporting surface, which prevents the drainage channel from being blocked by the sinking of the non-woven fabric above it, and also avoids tearing due to insufficient tensile strength of the non-woven fabric that could allow soil to enter and block the drainage channel. The water retention and drainage board can fully preserve the drainage space, completely avoiding the situation where plastic protrusions experience drainage problems due to the sinking of the non-woven fabric, thereby preventing the wilting and death of vegetation caused by poor drainage. **Product Use:** Used for rooftop greening, underground car roof greening, urban squares, golf courses, sports fields, wastewater treatment plants, public building greening, and road greening projects within parks.