The invention discloses multimedia subsystem local service triggering system and method and a relevant device, which are used for solving the problem that a user terminal can not use a large number of position relevant services provided by a local network and having no need of purchasing. The system comprises an application server, a proxy-call session control function device and a first service triggering function device which are positioned in the same network, wherein the proxy-call session control function device is used for receiving a local service request message transmitted by user equipment in the network and used for requesting the position relevant services and transmitting the message to the first service triggering function device ; and the first service triggering function device is used for selecting the application server capable of providing a service corresponding to a local service identification contained in the message according to the local service identification and routing the message to the selected application server.