With the rapid development of sharing manufacturing, its sharing models are gradually enriched, which has derived the manufacturing model of sharing production equipment and lines, and the innovation model of sharing product design, research and development capabilities. There are substantial co-opetitive relationships between the suppliers and demanders of sharing manufacturing since they normally belong to the identical industry. It is a significant problem to be solved urgently how to improve the profit of participants for model selection and decisions optimization in sharing manufacturing under co-opetitive relationships. Focusing on the problem, firstly, the two models composed of suppliers and demanders are ​​established respectively. Secondly, the optimal model selection strategies are given by analyzing the equilibrium profit. Finally, when the sharing model are win-win models is given by analyzing the optimal strategies. The results show that the optimal model selection strategies are mainly determined by the market potential and the proportion of core components, and the suppliers and demanders should select different models under different circumstances. In addtion, only the potential market and the proportion of core components are moderate, sharing models are win-win models for suppliers and demanders. Results provide useful management enlightenment for the model selection and decisions optimization of sharing manufacturing under co-opetitive relationships.