The invention relates to the technical field of sewage treatment, and discloses an anti-sewage backflow device for urban inspection wells based on the principle of electromagnetic induction, which includes a well wall and a slide rail. The top of the well wall is movably connected with an inspection well cover. The water inlet pipe is movably connected, the inside of the well wall is movably connected with a sliding assembly, the outside of the sliding assembly is movably connected with an electromagnetic assembly, the inside of the well wall is fixedly connected with a magnet one, the inside of the well wall is movably connected with a baffle, and the inside of the baffle is The second magnet is fixedly connected; through the interaction between the well wall, inspection well cover, water inlet pipe, sliding assembly, electromagnetic assembly, negative pole, positive pole, and copper rod, it can achieve anti-backflow after triggering when sewage backflow occurs The structure operates, which provides prerequisites for the start of anti-backflow, and this design will only start when the sewage is poured back close to the manhole cover, which is more in line with the actual situation.