Abstract: The construction of the new power system involves interaction and sharing of massive and heterogeneous data among multiple business systems, departments, and agents. The internal and external network environment and security situation of power data are becoming increasingly complex, and the vulnerability risk of data circulation increases. First, this paper analyzes the types and characteristics of data flow in the new power system, and summarizes the new situation faced by the security protection of power data circulation. Then, based on the high-performance traffic orchestration and multifunctional security gateway capabilities of the data processing unit（DPU）, the ubiquitous security boundary is constructed to enhance the security of power data cross-domain circulation. With the help of data-plane programmable technology, the dual-dimension security capabilities of network security and data security are communicated, and a DPU-based application scheme of collaborative protection technology for the cross-domain data circulation is proposed. Finally, this paper explains the deployment methods, values, and key technologies of DPU at different levels of power communication networks, and analyzes the challenges of DPU application in the power industry at present.