The invention provides a high-performance route forwarding method in cloud computing, relating to the field of network simulation. To solve a performance problem of cross-subnet data communication ina virtual network in a current Openstack host machine, the invention provides an SDN-based route control platform, a route table in a virtual network topology is mapped to a flow table in real time bybuilding a route decision layer and a data forwarding layer, consequently, forwarding of three layers of network data is controlled by a virtual route topology in the route decision layer, but an Openflow switch directly forwards a data packet. Further, a virtual network topology monitor module is designed to monitor route hop count of nodes in real time, guaranteeing forwarding fidelity of threelayers of network data packets and improving the performance of the virtual network. Creation of a typical network topological scene proves that the method is effective.