Starting from the theoretical perspective of collaborative governance，we explore the grass-roots community collaborative governance mechanism，the effect and influencing factors with taking Chaoyang District Maizidian street “Ask public policy” practice as an example. The result shows that the incentive of national policy，the common interests and obtaining social power are external impetuses and science and rationality of institutional design and facilitative leadership inside the cooperative body are internal impetuses for different social subjects to operate collaboratively. In the structure of grass-roots community collaborative governance，different social subjects play different roles under the function of participation，decision-making，integration，supervision and so on，outputting the obvious synergetic governance effect and promoting harmonious and orderly operation of the social system.