A polar code encoding method includes obtaining, by an encoding apparatus, to-be-encoded bits, a mother code length, and a first sequence. The first sequence includes sequence numbers of polarized subchannels. The sequence numbers of the polarized subchannels are arranged in the first sequence based on reliability of the polarized subchannels. The method also includes determining, based on the first sequence, polarized subchannels used to contain the to-be-encoded bits, and performing polarization encoding on the to-be-encoded bits to obtain an encoded bit sequence. The method further includes performing rate matching on the encoded sequence to obtain a rate-matched sequence. The method additionally includes outputting the rate-matched sequence.