Abstract: Provided is a method for disposing of contaminated deposit soil and recycled reclamation soil using the same and, more specifically, a method for disposing of contaminated dredged soil, the method comprising the steps of: seeding a mixed strain NIX51 (KACC81038BP) in the contaminated dredged soil to primarily dispose of contaminated materials in a bioreactor; and washing the degraded soil, which has been primarily disposed of, with a washing solution containing at least one selected from the group consisting of citric acid, oxalate, carbonic acid (H2CO3), and nitric acid, to secondarily dispose of heavy metals.