Fish and vegetable symbiotic double-filtering device

The utility model discloses a fish and vegetable symbiotic double filtering device, which comprises a primary filtering box, a planting box and a secondary filtering box, the primary filtering box and the planting box are both positioned above the secondary filtering box, and the primary filtering box is internally divided into a water inlet cavity, a filtering cotton cavity, a chemical filtering cavity and a siphon cavity through partition plates in sequence along the water inlet direction; a planting plate is arranged on the upper layer of the planting box, planting holes and planting cups are installed on the planting plate, the bottom of the planting box is connected with a brush cavity through a planting box water outlet pipe, and the interior of the second-stage filter box is sequentially divided into the brush cavity, a first-stage biochemical cavity, a second-stage biochemical cavity and a sterilization water outlet cavity through partition plates in the water inlet direction. The plant cultivation de