This application discloses a polar code-based interleaving method and apparatus, to resolve a problem existing in the prior art that when a code length is relatively long, an implementation process of reading a sequence obtained after random interleaving is relatively complex. The method includes: determining an interleaving matrix based on a target code length M of a polar code; and interleaving, based on the interleaving matrix, encoded bits obtained after encoding of the polar code, to generate interleaved bits.