In the operation of Chinese government organizations, there are a large number of inter-departmental collaborations, that is, the competent departments and cooperating departments work together to complete the tasks around a certain governance task. This paper analyzes the causes of the differences in the forms of interdepartmental collaboration, and points out the active role of the task coordinator in interdepartmental collaboration. Interdepartmental collaboration has the organizational function of breaking the fixed division of labor, condensing governance resources and releasing capacity signals. At the same time, different task attributes and their control elements shape different forms of collaboration, so the form of collaboration between departments often varies with the change of task attributes and control elements. In practice, the competent departments often actively compete for the attention of superiors through various means such as packaging collaborative tasks and central tasks, and creating public opinion atmosphere, and strengthen the overall planning of the coordinating departments with the attention of superiors. The investigation of the role differences and organizational mechanisms of different departments in the process of collaboration helps to enhance the understanding of the internal operation and logic of Chinese government organizations, and to think from multiple perspectives on how hierarchical organizations complete their tasks.