The invention discloses a method, application server and system for realizing service switching. By utilization of the method, application server and system for realizing service switching disclosed by the invention, a service triggering message reported by a service switching terminal can be received; a media server is controlled to play call holding prompt tone to a service holding terminal; then, after a service switching message reported by the service switching terminal is received, service switching and media consultation with a terminal corresponding to a switching service can be carried out according to switching service parameters in the service switching message; and furthermore, the media server is controlled to play corresponding tone to the terminal corresponding to the switching service. On the basis of the above mechanism, the embodiment can realize the service switching purpose by a key in a call on a common terminal; and compared with the scheme that a more advanced terminal is needed or a WEB server is additionally arranged in the prior art, the technical scheme has the advantages that the terminal and network element equipment do not need to be improved or additionally arranged in the invention, therefore, the deployment cost is reduced, the application universality is easily expanded, the practicality and the adaptability are relatively high, and in addition, the user experience is easily improved.