Dairy industry is the pillar of Heilongjiang Province. The contractual relationship of the dairy supply chain played a vital role in the dairy industry for development. The contractual relationship between the main dairy farming body and the dairy processing enterprise, as well as the impact of this contractual relationship on their cooperation in dairy supply chain were studied. Taking 366 dairy farming bodies in Heilongjiang Province as the main research objects, Likert scale was used to measure the factors affecting the contractual relationship and applied these factors to the correlation construction of dairy farming body and processing enterprise. Then, confirmatory factor analysis was used to collect data and made the conclusion that once dairy farming body perceived the opportunistic behavior and lacking of cooperation, the trust of dairy processing enterprise would be lost. Additionally, the satisfaction of dairy farming body on partnership also had a positive effect on the level of trust and commitment, the relative dependence and the perception of the partnerships, which made it possible to analyze how to strengthen the contractual relationship and provide theoretical basis for dairy industry development in Heilongjiang Province.