In collaborative manufacturing environment, the knowledge integration in collaborative process is very crucial, especially the heterogeneous information distributed among various cooperative suppliers. To tackle the optimization of knowledge consolidation in co-manufacturing, a knowledge integration with ontological framework is proposed in this study. First, by representing the collaborative business activities for cooperative suppliers, an architecture of knowledge integration with ontological schema is generated. The ontological model of knowledge concepts is explored in terms of the analysis of the ontological structure of knowledge. Aiming at the concept, an approach of ontology integration on the basis of ontological similarity is promoted. There are two portions included in this approach, mapping and combination, which are implemented through the analysis of similarity in two ontologies namely universal and regional. To integrate the two ontologies, the relations and restrictions among fields are definitely depicted by the Semantic Web Rule Language. Eventually, the presented framework is illustrated through a case study, and the outcomes satisfy the needs of knowledge combination to assure that the effectiveness of the presented method is confirmed.