This paper presents the framework of a power-dispatching automation system (PDAS) based on a virtual private cloud, which extracts advantages of technologies, such as a virtual private cloud, a virtual private network, an https protocol, etc. Unlike existing on-premise or public cloud hosted PDASs that are vulnerable and may be subject to blackouts due to extreme conditions, such as natural disasters or cyberattacks, the proposed framework operates more safely and securely under those conditions, while at the same time meeting the reliability requirements for power systems as well. This paper presents the theory, architectural design, characteristics, and implementation process of the system, as well as its reliability and cyber security measurements. The annual failure time of the proposed system is reduced from 61.2 to about 0.43 min, about 142 times less than those of existing PDASs. This framework has been implemented in the Lipu power system in China since May 2016. Results show that the proposed system is reliable, safe, and cost-effective, with a bright prospect for future applications.