The embodiment of the present invention provides a cloud dedicated line system and its service issuance and opening method, wherein the cloud dedicated line system includes a client, a government-enterprise private network, a government-enterprise cloud, and an SDN controller; wherein, the client is deployed with several client terminal devices CPE, the government-enterprise private network is deployed with several government-enterprise CEs and a cloud user edge router CloudCE, and the government-enterprise cloud is deployed with a cloud gateway; the CPE is connected to the government-enterprise CE, and the CloudCE is connected to the cloud gateway; the SDN controller is used to control the client and For the government-enterprise private network, a Vxlan tunnel with CPE and CloudCE as the endpoint is established to realize the cloud private line between the client and the government-enterprise cloud. The system and method provided by the embodiments of the present invention realize cloud access on local sites and secure access between sites, simplify the framework process, save costs and equipment resources, solve the problem of complex provisioning configuration, and simplify the provisioning process.