The construction of digital twin cities has become an important direction for the development of smart cities and plays a key role in promoting the transformation of urban governance models. From the perspective of collaborative governance, taking the CIM platform of Shenzhen City as a case, this paper analyzes the cross departmental collaborative mechanism in the construction of digital twin cities, deeply reveals the constraints of deep-seated obstacles on the effect of collaborative governance, and proposes countermeasures to optimize the collaborative governance path of digital twin cities and improve the modernization level of urban governance.