A route priority configuration method, a device, and a controller. The controller receives an interface creation request for creating a layer 3 interface on a target device, where the interface creation request carries an IP address and a subnet mask. The controller generates a direct route of the layer 3 interface based on the interface creation request; allocates a route priority to the direct route according to a preset allocation rule; and sends the direct route and the route priority corresponding to the direct route to the target device. According to the embodiments, direct routes generated based on a same IP address can correspond to different route priorities, to avoid a case in which direct routes advertised by different distributed gateways form ECMP, and improve route priority configuration efficiency.