The utility model discloses an initial stage rainwater split -flow filter device, include the reposition of redundant personnel three -way pipe, filtering ponds and the delivery pipe that link to each other with rainwater riser lower extreme, filtering ponds are located the below of reposition of redundant personnel three -way pipe, the delivery pipe is located filtering ponds with one side of reposition of redundant personnel three -way pipe, the reposition of redundant personnel three -way pipe be equipped with the drain pipe that links to each other with the rainwater riser and with the overflow pipe I that the delivery pipe links to each other, be equipped with filtering body in the filtering ponds, the perforated plate will two parts about filtering ponds fall into, the top of filtering ponds is for planting the groove, the lower part of filtering ponds divide into the storage water tank, the planting groove constitutes cross filtering body, the cartridge has a capillary pipet on the perforated plate the upper portion of storage water tank be equipped with with the overflow pipe II that the delivery pipe is connected. The utility model discloses can thoroughly purify the initial stage rainwater.