To explore the optimal safe utilization model for mildly Hg-contaminated farmland, this study selected rice-wheat rotation farmland with mild Hg pollution in Nanhu District, Jiaxing City. A four-year randomized block experiment was designed to screen low Hg accumulating rice varieties and compare passivators, as well as a two-year experiment was conducted to evaluate eight different safe utilization models. Hg content in brown rice was measured at the harvest stage of rice. After four years of mild Hg contamination field experiments, seven rice varieties with low Hg accumulation were preliminarily screened: Yongyou 538, Jiahexiang 1, Xiushui 14, Nanjing 46, Ning 84, Jia 58, and Yongyou 1140. The experimental results indicated that for mildly Hg-contaminated farmland, it is not suitable to apply passivators such as quicklime, organic fertilizers, and inorganic sulfur. It is more suitable to choose a combination of low Hg accumulation rice varieties and deep tillage as a safe utilization mode, which is safe and economically effective for the research area.