A method for ensuring reliability in a network is disclosed, including: distributing, based on service flow, services to multiple home functions entities of the coupled function entity, where the multiple home function entities have identical functional characteristics in the network; taking over, by a first home function entity operating normally, work of a second home function entity to be switched if determining to switch between the multiple home function entities. Through the method, if one or more of the multiple home function entities is in failure, other home function entities may take over work of the function entities in failure, which ensures the continuity of data flows of services and prevents the services from being interrupted, greatly improves reliability and load balancing ability of end-to-end QoS architecture. Furthermore. There is no limitation on network architecture and the method is applicable to networks with any scales.