The invention discloses a water treatment integrated device. The water treatment integrated device comprises a multimedium filtering device and a membrane biological reaction device, wherein the multimedium filtering device comprises a multimedium filtering pool body, a pretreated water inlet pipeline and a first water outlet pipeline, the multimedium filtering pool body is sequentially provided with a multimedium supporting layer and a multimedium filler layer from bottom to top, the pretreated water inlet pipeline is communicated with the multimedium filler layer, the first water outlet pipeline is communicated with the multimedium supporting layer, the membrane biological reaction device is communicated with the multimedium filtering device by virtue of the first water outlet pipeline and comprises an aerobic reaction pool and a membrane component, the aerobic reaction pool is communicated with the first water outlet pipeline, and the membrane component is arranged in the aerobic reaction pool and comprises a filtering unit and a water production outlet. According to the water treatment integrated device, as the multimedium filtering device is communicated with the membrane biological reaction device by virtue of the first water outlet pipeline, pollutants in pretreated water can be continuously treated and can also be treated sequentially according to the pollutant components in the pretreated water, so that the treating effect is better, and the effluent quality is improved.