The invention discloses a cultivated land soil remediation system. The cultivated land soil remediation system comprises a shell, wheels arranged at the bottom of the shell, a garbage collection box fixed to one side of the shell, a dustproof cover arranged on the shell, a feeding machine located on one side of the shell, a remediation chamber arranged in the shell and a primary screening chamberarranged in the shell. The remediation chamber comprises a third sieve plate, a plurality of second cams arranged at the bottom of one side of the third sieve plate, two first inclined plates locatedbelow the third sieve plate, a plurality of spray heads adjacent to the first inclined plates, a pump body connected with the spray heads, a spiral stirring shaft located below the inclined plates anda bottom plate located below the spiral stirring shaft; and according to the method, an in-situ remediation mode is adopted, the cultivated land soil is subjected to centralized treatment, the soil before cultivation is remediated through the processes of crushing, primary screening, refining, remediation liquid spraying and the like, the activity of the soil is restored, and compared with a traditional ploughing mode, the labor force is reduced, and the problem of heavy metal pollution removal is solved.