The drilling engineering design of a well needs collaborative work of designers from multidisciplinary fields such as geology, reservoir engineering and drilling engineering, or designers distributed in different departments. Because there is closely data relevance among every parts of the drilling engineering design which needs the designers in different departments to exchange a lot of data and documents according to a certain design process, any delay in parts of design process will affect the timeliness and accuracy of the whole drilling engineering design. The authors integrated workflow theory into process management of drilling engineering collaborative design system, built workflow management model of Drilling Engineering Collaborative Design System. The paper analyses function of the five sub-modules in this model in detail combining realization process of the system. So it provides an effective method for process management of Drilling Engineering Collaborative Design System, and improved actual operating efficiency of the system.