The invention discloses an intelligent building intercommunication system. The system comprises an entrance machine, a visual intercommunication indoor unit, a server and a mobile terminal, the entrance machine comprises a button module, an iris acquisition module, an iris recognition module, a voice acquisition module, an image acquisition module, a data storage module, a control module and an unlocking module, the entrance machine uploads acquired sound and image information of visitor personnel to the server, the server sends the sound and image information to the visual intercommunication indoor unit and the mobile terminal, and the visual intercommunication indoor unit comprises a voice playing module, a display module, a timing module and a feedback module. According to the system, the identity can be rapidly and accurately recognized through an iris recognition technology, the waiting time is accumulated through the timing module, once time is up, the feedback module feeds the information back to the server, the server sends the visitor information to the mobile terminal, a user can understand the visitor information in a remote manner, remote control of a door lock is realized, convenience is realized, and the safety of the users is improved.