The invention discloses a method for using an alarming system to achieve three-party communication. The method comprises the steps that an alarm giver dials an alarming call, a public security three-in-one platform pushes the alarming call to a one-key alarming platform, a wiz platform pushes position information of the alarm giver to the one-key alarming platform, the one-key alarming platform starts interphones around the alarm giver, the public security three-in-one platform pushes alarming voice to the one-key alarming platform, the one-key alarming platform plays communication voice of the alarm giver and an alarm receiver in real time to the started interphones, a policeman presses an interphone PTT talkback button for voice communication among started interphone groups, the one-keyalarming platform pushes the voice flow generated by the interphones to the public security three-in-one platform, and thus three-party communication of the alarm giver, the alarm receiver and the policeman is achieved. By means of the method, the communication voice flow of the alarm giver and the alarm receiver is transmitted to the interphones in real time to be received by the policeman in real time, the policeman in the groups is timely informed to receive alarm and allocate policemen to handle the case, the efficiency of allocating the policemen is improved, and the loss caused by disasters is reduced.