The nutritional absorption of plants is mainly completed by the roots, and the formation of iron films in the roots of plants directly affects the absorption of nutrients. A good ecological environment can promote the formation of iron films on the root surface of plants, and thus accelerate the absorption of nutrients by plants. However, a bad ecological environment will endanger the growth of plants. If plants are in a polluted ecological environment for a long time, then plants will absorb harmful substances. If they finally reach people's tables, they will inevitably have a great impact on people's health and safety. The research found in this paper found that heavy metals have a direct effect on the growth of rice. The experimental research analysis found that the concentration of MeHg in DCB of three varieties of rice was 1.8-2.6 times that of + P treatment under -P treatment, indicating that the iron film had an effect on MeHg in solution. Has a very strong adsorption effect. That is, heavy metals are very easily absorbed by the iron surface of the plant roots.