A distributed collaboration design environment is proposed in this paper, based on the analysis of current aerospace products' situation and problems. A sole defined and operated data source, Task Unified Model (TUM), is introduced in the coordinate design environment to commonly describe the knowledge, task, object, personnel and process. The definition of TUM, organization, views conversion and operation mechanism are detailed discussed. The distributed design environment, APEngine, is built on the basis of Eclipse RCP and Web Portal technology, which realized the TUM implementation, live example utilization and operation through the entire product design process. It has been proved in the design and utilization in an aerospace product that research work in this paper is highly useful in engineering application.