Biodegradable packaging, as a high environmental level packaging, its promotion can reduce carbon emission and plastic pollution. A fuzzy-TOPSIS decision mechanism model under random forest optimization is developed to simulate the process of consumer choice between biodegradable packaging, recycled paper packaging, and conventional packaging. Based on this model, a tripartite evolutionary game model is established among consumers, packaging enterprises, and government, and the probability change process of each party's strategy is obtained. Finally, the influence of factors such as subsidy strength and demand uncertainty is obtained through sensitivity analysis. The results show that, in the initial conditions, the market share of biodegradable and recycled paper packaging continues to increase to nearly 70%. The increase in government subsidies first increases the market share of biodegradable and recycled paper packaging. It later only increases the share of biodegradable packaging, leading to an overall reduction in carbon emissions.