Automatic extension dial-back method and system

The present invention provides an automatic dial-back method and system, which relates to a relay IP voice technique. The present invention solves the problem that the opposite part can not dial back when a user gets an outside line with an extension. The technical proposal comprises the following steps: first, the system records information related to outside calls dialled by all extensions and stores the information in calling information records; then, the system retrieves the calling information records according to outside call numbers dialled in, and judges whether the information related to the outside calls exists in the calling information records or not; if the information is not available, enter a normal calling process and end the current dial-back process; otherwise, prompt outside call users to select the extension numbers recorded; whether the outside call users select the extension numbers recorded or not is further judged; if the outside call users select the extension numbers recorded, the system automatically dials and connects the recorded extension numbers selected by the outside call users and ends the current dial-back process; otherwise, enter the normal calling process. The present invention is convenient for users, and suitable for IP voice gates or group telephones.