A network virtualization configuration method, a network system, and a device, where the method includes creating a switch virtual machine (VM), where the switch VM is configured to run a virtual switch, responding to a Peripheral Component Interconnect (PCI) scanning of the switch VM, configuring, using a physical function (PF) driver, a PCI Express (PCIE) device to allocate a corresponding network resource to the switch VM, and initializing the PCIE device using the PF driver, where a default forwarding rule of the initialized PCIE device includes setting a default forwarding port of the PCIE device to a VF receiving queue (VF 0) corresponding to the switch VM. Hence, a cross-platform virtual switch solution can be implemented, thereby improving flexibility of deploying a virtual switch, and implementing compatibility with different hypervisors/VM monitors (VMMs).