Embodiments of the present application disclose a message processing method, apparatus, and system, which are applied to SDN. An application sends a first message to a controller, and the message includes service content used to describe a service requirement. The service content includes target information and operation information. The application receives a second message sent by the controller. A payload of the second message includes solution information of at least one solution used to implement the service content. The application obtains the solution information of the at least one solution based on the payload of the second message. Therefore, a service requirement is converted into a control requirement between an application plane and a control plane.