Abstract: The value of data depends on its liquidity. Breaking data barriers and promoting cross-departmental data sharing is a necessary requirement for activating the data value and promoting the development of digital economy. However, it is difficult for the existing institutional path to bridge the trust between organizations, reconstruct the organization's benefit distribution mechanism and solve the problem of data ownership. Therefore, the Byzantine Generals Problem of data sharing across departments cannot be really cracked. With the rapid development of new technologies such as artificial intelligence, block chain and privacy computing, shaping the data flow space with new technologies has become a new breakthrough. Based on three innovative cases of Government Xiaowu, Block Chain + Tax Equity Transfer and Health and Medical Data Application Open Platform, the new mechanism of government cross-depart- ment sharing equipped with new technologies is discussed. It is suggested that the core of cracking the government's cross-departmental data sharing is to shape a data "flow space" based on new technologies, including virtual space based on 5G+VR technology, distributed ledger space based on block chain and "isolation space" based on privacy computing. The spatial structure and movement mode of data flow in different technical frameworks can further affect the depth and breadth of data flow. In the future, the expansion and governance of data flow space will open a new way for cross-departmental data sharing.