Collaborative model and process model for complex machinery products collaborative design are studied in this paper. The authors propose a layer collaborative model, which is used to describe the layer collaborative process in complex machinery design firstly. It contains design layer dimension, design objective dimension, design cycle/period dimension and design constraint dimension. The model is described by state-space method and built up by object layer dividing strategy. Then the authors present a process model for collaborative design and definite it in formalization, which is used to describe design process of each layer in collaborative model. At the same time activity type, activity state, activity operation and activity process in collaborative design are analyzed. It affords information basis to organize complex machinery products collaborative design orderly on web by building the multi-layer collaborative model.