<abstract> <p>With the rapid increase in the number of infected people in COVID-19, medical supplies have been increasing significantly. Medical waste treatment scheme selection may have long-term impacts on the economy, society, and environment. Determining the best treatment option is a considerable challenge. To solve this problem, in this paper, we proposed a multi-criteria group decision making (MCGDM) method based on single-valued neutrosophic numbers and partitioned Maclaurin symmetric mean (PMSM) operator. Because of the complexity of the medical waste treatment scheme selection problem, the single-valued neutrosophic numbers are applied to express the uncertain evaluation information. For the medical waste treatment scheme selection problem, the factors or criteria (these two terms can be interchanged.) in the same clusters are closely related, and the criteria in different clusters have no relationships. The partitioned Maclaurin symmetric mean function can handle these complicated criterion relationships. Therefore, we extend the PMSM operator to process the single-valued neutrosophic numbers and propose the single-valued neutrosophic partitioned Maclaurin symmetric mean (SVNPMSM) operator and its weighted form (SVNWPMSM). Then, we analyze their properties and give typical examples of the proposed operators. An MCGDM model based on the SVNWPMSM aggregation operator is developed and applied to solve the medical waste treatment scheme selection problem. Finally, the validity and superiority of the developed model are verified by comparing it with the previous methods.</p> </abstract>