The collaborative relationship in the “Internet +" manufacturing industry is a complex network. To grasp its inherent laws fully to realize the transformation and upgrading of the manufacturing industry integrated with Internet, a model of optimization and upgrading of the collaborative relationship in the `Internet + manufacturing industry, which is a closed-loop feedback control model under a control theory framework, is proposed. An evaluation index system based on the theory of the complex social networks was designed, and an empirical analysis based on the micro operation data of a large collaboration platform for the `Internet + manufacturing industry was done. The results show that `Internet + can significantly improve the quality of the manufacturing collaboration relationship and improve overall collaboration and innovation performance.