PURPOSE: Method and device for improving water environment due to the floor cleaning of polluted river are provided to improve water environment of river by effectively cleaning the floor of polluted river and collecting and disposing pollutants. CONSTITUTION: A device for improving water environment due to the floor cleaning of polluted river comprises a pair of barriers(10), a water pipe(20), and a dehydrator. The barriers are respectively installed across the upper and lower parts of a region(7) to be cleaned. Both ends of the water pipe are inserted into the water hole of the barrier to send water of an upper part than the region to be cleaned, to a lower part. The dehydrator dehydrates or filters water containing dredged soil or pollutants.
