This paper first analyzes the problems of traceable information sharing between dairy suppliers and manufacturers, and proposes the theoretical and practical significance of building related evaluation system of information sharing. And then the traceable information in dairy supply chain based on batch management is analyzed and a principal-agent model is developed to assess the value of information sharing between dairy suppliers and manufacturers. Results show that when the information sharing between dairy suppliers and manufacturers reaches a certain degree, the Pareto optimality of the overall supply chain can be achieved.