This application relates to the field of communications technologies, and discloses an interleaving method, a deinterleaving method, and an apparatus, to improve randomicity of polar code interleaving. The method is: obtaining a to-be-interleaved bit sequence, where the to-be-interleaved bit sequence includes L, subsequences, the L subsequences include S subsequence groups, the S subsequence groups include at least a first subsequence group and a second subsequence group, the first subsequence group includes at least two subsequences, the second subsequence group includes at least one subsequence, and L is a positive integer greater than 1; and interleaving the subsequences in the first subsequence group in a first interleaving manner, and skipping interleaving the subsequence in the second subsequence group or interleaving the subsequence in the second subsequence group in a second interleaving manner.