In this paper, the mechanism of workflow management based on ontology of multi disciplinary collaborative design is studied. Based on the integrative research of key technologies of semantic technology and semantic retrieval and workflow management, an ontology-based workflow framework of multi-disciplinary collaborative design is put forward. Models of workflow-related elements on different levels were built up according to subjects related in collaborative design. An ontology-based workflow model library of multi-disciplinary collaborative design is set up by using RDF. The currently popular ontology retrieval strategy is analyzed, and an ontology model search engine in workflow of multidisciplinary collaborative design is set up by combining the keywords-based with ontology-based semantic search.