A collision avoidance method for subscribers to fight for a right to speak of a multi-party conversation in a digital intercommunication system includes: sending a frame of instructions from the transmitting subscriber to the receiving subscribers for declaring a beginning of a fight for phase; in a subset of frame moments during the fight-for phase, sending maintenance information by the transmitting subscriber to the receiving subscribers; in another subset of the frame moments during the fight-for phase, broadcasting a request for the right to speak by the receiving subscribers intending to obtain the right to speak in turn, the fight-for phase not closing until at least one of the receiving subscribers sends out a request message; hearing the request message, ceasing fighting for the right to speak by the other receiving subscribers; and the receiving subscriber obtaining the right to speak as a new transmitting subscriber and beginning to speak.