The present invention discloses a channel state information feedback method and apparatus. User equipment determines a PMI and a CQI, and a feedback expression manner of the PMI and the CQI, where the feedback expression manner includes a first or a second feedback expression manner, and sends the PMI and the CQI to a network device in the determined feedback expression manner of the PMI and the CQI, where the first feedback expression manner includes: using T CQI values to express CQI of M codewords, and using one PMI value to indicate one PMI, where T is less than M, and there is at least one CQI value that can express CQI of at least two codewords; and the second feedback expression manner includes: using M CQI values to express CQI of M codewords. The present invention may be applied to a scenario in which an antenna quantity increases.