In order to study the synergistic effect of dairy quality chain, introducing GERT network（Graphic Evaluation and Review Technique）, and proposing the means to establish collaborative GERT network Model of dairy quality chain. Firstly, through analyzing the characteristic of dairy chain collaboration GERT model, defining parameters of quality dairy chain; Secondly, according to the characteristics of dairy quality chain, designing the dairy quality chain collaborative GERT network; Furthermore, through analyzing the mass flow among nodes of dairy quality chain collaborative GERT network, synergistic effect between fluctuation variance of mass flow and average of mass flow is served as indexes of dairy quality chain collaboration; In the end, the practicability of this model and algorithms is demonstrated by the case study.