[Objective] Due to the serious heavy metal lead pollution in the farmland around the rare earth mining area in Southern Jiangxi Province, we aim to study the migration and transformation of heavy metal lead in the farmland soil in this area in order to provide a basis for lead pollution control in mining area.[Methods] The leaching amount of heavy metal lead was observed by simulated acid rain leaching experiment, and the experimental results were analyzed by response surface methodology.[Results] As the leaching amount of lead increased with time, it showed two stages of rapid and slow decline. With the decrease of pH value, the leaching amount of lead increased first and then decreased with the increasing of leaching intensity. When the concentration of exogenous lead increased, the leaching amount increased with the decrease of pH value and the increase of leaching intensity. Response surface software was used to fit the experimental data by multiple regression. The pH value and concentration of lead in culture were significant in the interaction term.[Conclusion] The degree of lead pollution was positively correlated with the release of lead. The pH value of acid rain had an important influence on the release of lead in contaminated farmland.