Environmental remediation of heavy metal-mining sites can improve human well-being through pollution risk control and improved ecosystem services. A cost-benefit dynamic analysis for the multiple stakeholders involved in the project can better explain the overall efficiency and provide guidance for further mine remediation. Taking Asia's largest monomeric realgar mine environmental remediation project (MER) as a case, we conducted, for the first time, a dynamic cost–benefit analysis for multiple stakeholders over a 60-year period regarding environmental risks, health risks and ecosystem services. The results show that by improving the environment and ecosystem, the payback period is expected to begin 5 years after the end of the project, with a benefit‒cost ratio of 2.71 by 2050. Local residents, the direct beneficiaries, receive 13.2% of the benefits, which come from agricultural soil remediation projects (66.6%) and health risk reduction (33.4%). The government, as an investor, receives 3.3% of the benefits. Downstream water users are the main beneficiaries, receiving 76.5% of the total benefits, mainly from the benefit of As-contaminated water purification (97.9%). Compensation from downstream beneficiaries for improved water might be channeled into sharing the burden of MER implementation. Notably, the intercropping remediation of hyperaccumulators and low-accumulation crops for agricultural soils in MER provides employment and sustainable agricultural income during and after remediation, respectively. This green and sustainable remediation model improves both the environment and the livelihood of residents and should be recommended for nearly one million mining sites worldwide.