The invention discloses a service suspension method, which comprises: when an user equipment stationed in a group field needs to initiate a circuit field service, the core net equipment of the group field reserves the group network resource of the user equipment according to received indication; when the user equipment is performing a service, saves the descending service data and / or stopping sending the up-link data of the user equipment, and converts to circuit field communication network to perform circuit field service; or, when the user equipment is not performing service, then converts to circuit field communication network to perform circuit field service. The invention further discloses a corresponding treatment system for returning the circuit exchange field service to the conventional network, a user equipment, an evolvement base station, a mobility management entity, a service gateway and a group data network. Applying the invention can reduce the time delay before CS service while processing CS fallback, and further avoids resource waste.