To explore the optimal safe utilization model for mildly mercury-contaminated farmland, this study selected a rice-wheat rotation system on mildly contaminated land. We conducted a four-year randomized block experiment for rice variety screening and immobilizer comparison, and a two-year experiment evaluating eight different safe utilization models. Mercury content in brown rice was measured at harvest. After four years of field trials on mildly mercury-contaminated farmland, the following results were obtained: Firstly, seven rice varieties with low mercury accumulation were preliminarily identified: Yongyou 538, Jiahexiang 1, Xiushui 14, Nanjing 46, Ning 84, Jia 58, and Yongyou 1140. Two varieties were not recommended for large-scale planting in mercury-contaminated fields. Secondly, the application of quicklime, organic fertilizers, and inorganic sulfur as immobilizers was found to be unsuitable. Finally, combining low-accumulation varieties with deep plowing was determined to be the most suitable safe utilization mode, proving both safe and cost-effective for the study area.