Embodiments of the present invention provide a channel encoding and decoding method and apparatus, where a channel encoding method includes: acquiring, by an encoder, an information bit index set; generating, by the encoder, a second bit vector according to a to-be-encoded first information bit and the information bit index set; and performing, by the encoder, Polar code encoding on the second bit vector to generate an encoded first code word. In technical solutions of the present invention, an encoder first acquires an information bit index set, generates a second bit vector according to a to-be-encoded first information bit and the information bit index set, and then performs Polar code encoding on the second bit vector to generate an encoded first code word.