Purpose <p>To elucidate the response of soil ecosystem multifunctionality (EMF) to microplastics (MPs), with particular emphasis on the effects of MPs’ type, dose, and particle size.</p> Methods <p>A 144-day soil incubation experiment was conducted using two common MPs: polyethylene (PE) and polyvinyl chloride (PVC). The experiment employed three doses (0.1%, 1.0%, and 5.0%) and two particle sizes (150 mesh and 500 mesh). Soil EMF was assessed by measuring soil available nutrients (dissolved organic carbon, DOC; available nitrogen, NO₃⁻-N and NH₄⁺-N; and available phosphorus, AP), enzyme activities (urease, invertase, and alkaline phosphatase), and microbial community composition (analyzed via phospholipid fatty acids, PLFA).</p> Results <p>Both PE and PVC significantly increased DOC and AP, whileNO₃⁻-N exhibited a mixed response and NH₄⁺-N remained unchanged. Soil enzyme activities generally increased with MPs, particularly in PE treatments, whereas PVC treatments showed decreased activity at higher doses. PLFA analysis revealed that the microbial community structure varied depending on the type, dose, and particle size of MPs. Soil EMF consistently increased under both types of MPs, with larger-sized MPs and PVC treatments showing greater effects. Soil enzymes (including invertase, urease, and alkaline phosphatase), soil DOC and AP, as well as the relative abundance of general bacteria and G⁻ bacteria, were the important variables for predicting the impact of MPs on soil EMF, and soil enzymes exhibited the highest contribution to the soil EMF.</p> Conclusion <p>Our findings highlight the complex impacts of MPs on soil ecological functions and underscore the need for further research to comprehensively evaluate the effects of MPs pollution on soil ecosystems.</p>