Method and apparatus for configuring a triggering condition of a beam failure event and a communication system. The method includes: a network device configures a UE with one or more control channel monitoring groups, so that when the UE detects that all beams to which a monitoring group corresponds fail in transmission, the UE reports beam failure event of the monitoring group fails in transmission; wherein, each monitoring group corresponds to one or more pieces of downlink control information (DCI). By configuring regarding the triggering conditions of the beam failure events, detection and report of beam failure in more complex scenarios may be supported, such as a scenario where one piece of DCI is transmitted in multiple control resource sets, and a scenario where multiple pieces of DCI are transmitted in one control resource set, etc.