Collaborative Optimization has been studied a lot in recent years as an algorithm. The Collaborative Optimization is a strategy of a secondary optimization based on the consistency constrained optimization methods. Take ADT’s transmission system as research object, establish collaborative optimization model of the 45 tons ADT transmission system. Set vehicle dynamics and fuel economy as the ultimate optimization goal and then do collaborative optimization. It shows that the results of collaborative optimization methods is better than traditional design. The result is applied to the design of 45 tons ADT transmission system, it has a practical engineering significance.