The invention provides an SDN-based cross-domain container virtual network establishment method, through which virtual two-layer network communication of cross-domain docker container clusters belonging to a same user and flow isolation of container clusters belonging to different users can be achieved. In general, the method mainly comprises the following steps: address reuse, that is, virtualized and address-reusable network abstraction is provided for the users on network infrastructure shared by all tenants in a hybrid cloud through the network virtualization technology; two-layer communication, that is, basic cross-domain virtual network functions are provided to meet internal network requirements of applications; and tenant isolation, that is, network isolation is provided for dockercontainers belonging to the different users.