Abstract: To solve the task scheduling problem in collaborative design stage of virtual prototype for complex products,a qualitative and quantitative model is established,and a strategy to solve the model based on genetic algorithms is proposed.By introducing tacit knowledge of the subject and object,this model synthesizes the impact of qualitative indexes and quantitative indexes on collaborative design.Using this strategy,the optimal solution of the model can be obtained rapidly under the constraints of tasks.Finally,a detailed example is given to confirm the model and its solving strategy,which can be used to reduce the project duration greatly.