It relates to computer communication technology. A method and system for transmitting voice messages are disclosed. The method includes: voice data collected by the first intercom terminal are received; whether the size of the voice data collected reaches a predefined threshold are circularly detected; and when the size of the voice data collected reaches the predefined threshold, or when the voice data collected doesn't reach the predefined size but contains a voice message terminator, the voice data collected are upload to the transit server via a predefined network, to realize asynchronization between voice data collection and uploading. Thus the problem of the prolongation of the intercom data transmission time associated with existing processes is solved by such an effective intercom data transmission method. In this method, the collection and uploading of the voice data can be done asynchronously, thus the delay of intercom can be reduced and the experience of the users of intercom terminal can be improved.