Provided are a method and device for realizing network slicing, and a controller. The method comprises: creating one or more embedded network slicing layers between a physical network layer and a service layer, wherein each network slice in the network slicing layer is created by means of a process comprising: creating multiple virtual network elements; employing a tunneling technique to create virtual links between the virtual network elements; and establishing an inclusive relationship among the network slices, the virtual network elements and the virtual links.