1. A method for callback processing in telecommunication capability opening, comprising: receiving, by a telecommunication capability opening server, a telecommunication capability application programming interface (API) call request sent by a client, wherein the telecommunication capability API call request comprises a callback information parameter, wherein the callback information parameter is an address of a callback function of a widget, and wherein the address of the callback function of the widget comprises a mobile phone number, a widget identifier, and a correlator; performing, by the telecommunication capability opening server, call processing according to the telecommunication capability API call request; generating, by the telecommunication capability opening server, a callback message according to the callback information parameter; negotiating, by the telecommunication capability opening server, with the client to set up a long connection for pushing the callback message; and pushing, by the telecommunication capability opening server, the callback message to the client through the long connection, wherein the long connection is configured to push callback messages of different applications and/or different pages to the client.