Embodiment of the present invention is described for the audio conversion method and apparatus, it belongs to the communication technical field. Receiving a voice switching request carrying the source mobility management entity, the terminal identifier of the first communication network, the terminal is a terminal to be switched as transmitted by the (MME) that is currently in use, and the target base station identifier;: the method First communication if the network is a preset communication network, the terminal is a first Internet contact is used to contact that currently have voice conversion efficiency of the a second communication network used in a local request from the communication network protocol multimedia subsystem ( sending the IMS) - required the contact is also conveyed to the terminal identifier; And if it is sent by the IMS as a terminal notification message is received indicating that it has a voice conversion performance, while performing voice conversion processing, or sent by the IMS in accordance with the target base station identifier and the terminal identifier to the terminal voice conversion performance, If the notification has not not represent the message is received, transmitting the converted status notification message to the source MME. It may use the present invention to reduce the waste of resources.