IMS service implementing method based on customer terminal, apparatus and system thereof

The invention discloses a method, a device and a system for realizing client end based IMS service. The method comprises the following steps: a client end on the user equipment initiates an IMS service request; a calling session control functional entity on the network side forwards the service request to a corresponding application server; the application server receives and processes the service request, and by the calling session control functional entity, a response message of the service request is sent to the client end on the user equipment; and according to the response message and anIMS service logic message, the client end ends the IMS service or initiates a new IMS service request. Due to the adoption of the invention, the execution of the IMS service logic can be realized on the client end on the user equipment, thereby enhancing network performance and improving the flexibility of realizing the IMS service.