In the practice of various Internet-based sharing economies, environmental issues of shared products become more prominent and urgent. By analysing the relationship among government, enterprises, and consumers, this paper develops a system dynamics model based on the evolutionary game theory to explore the quantity change pattern of environment-friendly products in a sharing industry. A discrete dynamic system simulation of the quantity change process takes shared bikes in Beijing as a case study. The simulation results are consistent with the analysis of evolutionary game theory. The results show that government subsidies to both enterprises and consumers can lead to higher quantities of environment-friendly shared products, while consumer subsidy is better than enterprise subsidy. In addition, governments and enterprises need to ensure moderate investments to improve consumer experience and environmental awareness.