A soil and water quality improvement method includes the following steps. An electrode element is disposed into a tubular body and he tubular body includes a plurality of through holes formed therein. The tubular body is then buried in a growing medium to be improved. Afterwards, ozone water is introduced into the tubular body and the ozone water is spread through the through holes into the growing medium to carry out an operation of sterilizing, and then electricity is conducted into the electrode element to carry out electrolysis. After the operations, an inspecting element is used to inspect the growing medium. Finally, the nutrition additive is conducted into the growing medium through the tubular body to complete the improvement of the growing medium, allowing a contaminated growing medium to be reused for cultivation.