This application provides a method and an apparatus for configuring a service, which help to implement automatic configuration of a service and improve efficiency. The method provided in this application includes: obtaining, by an NaaS device, a contract of a service, where the contract includes identifier information and a condition, the identifier information is used to identify a first device group, the first device group includes a device that provides the service, and the condition is a communication requirement corresponding to the service; obtaining, by the NaaS device, information about a network device group according to the identifier information and the condition; obtaining, by the NaaS device, a first forwarding rule according to the condition, where the first forwarding rule corresponds to the network device group; and sending, by the NaaS device, the first forwarding rule and the information about the network device group to a controller.