Sewage treatment device capable of performing multi-stage filtration on sewage

The invention discloses a sewage treatment device capable of performing multi-stage filtration on sewage, relates to the technical field of sewage treatment, and aims to solve the problems that an existing sewage multi-stage treatment device generally needs to be provided with a plurality of tank bodies for conveying and guiding materials, so that multi-stage treatment measures can be completed, the overall occupied area of the device is large, and the treatment efficiency is low. The second-stage filtering mechanism is installed below the first-stage filtering mechanism and is in flange connection with the first-stage filtering mechanism through a flange plate, the number of the third-stage filtering mechanisms is four, and the four third-stage filtering mechanisms are mutually welded and connected and are all arranged below the second-stage filtering mechanism; the periphery of the lower surface of the second-stage filtering mechanism is fixedly connected with a third-stage filtering mechanism through a fir