Bio slow-filtrating device for rain water accumulation

The utility model discloses a rain-water storage biological slow filter, which relates to a rain-water reclamation and utilization system. The filter comprises a rain-water pipe and a water storage pool, wherein the rain-water pipe is communicated with the water storage pool, and a clear water pool is added aside the water storage pool, and at least a slow filtering sand box which is communicated with the clear water pool and the water storage pool is partly arranged on the connection between the clear water pool and the water storage pool, and filtering matter is arranged in the slow filtering sand box. The slow filter retains the good effect of removing sewage, simplifies the operation process, improves the operation effect and effectively reduces the manufacturing cost.