A method and system for managing a modulation and coding scheme (MCS). The method includes: a base station obtaining a downlink channel quality indicator (CQI) when a block error ratio of a trunking terminal reaches a pre-stored block error ratio threshold; the base station comparing a current CQI of a group with a CQI locally stored and reported by the group, wherein the CQI reported by the group is the minimum value in received CQIs reported by trunking terminals in the group respectively; and if a comparison result is that the current CQI of the group is smaller than the CQI reported by the group, the base station initiating an operation of updating an MCS value.
