A mute processing method used in a multi-person communication system is provided. The method is capable of automatically sending mute frames when there are no sound inputs from terminals of the multi-person communication system. The method includes the steps of: collecting input signals from a microphone; calculating an energy level of the input signals within a present time span; obtaining a maximum amplitude of the input signals within the present time span; sending a mute frame if the energy level and the maximum amplitude of the input signals within the present time span are respectively less than a predetermined energy level and a predetermined amplitude, otherwise, coding the input signals within the present time span; and outputting the mute frame or coded signals. A related apparatus is also provided.