This application provides a channel encoding method and a communication apparatus. A second communication apparatus obtains a first parameter of a first communication apparatus, where the first parameter includes a parameter related to channel coding and decoding and a reinforcement learning training parameter. The second communication apparatus determines, based on the first parameter, first code construction information for constructing a coded bit sequence based on an information bit sequence during channel encoding; and after sending the first code construction information to the first communication apparatus, performs channel encoding and decoding on communication data between the first communication apparatus and the second communication apparatus by using the first code construction information to improve channel encoding performance and further improve communication reliability.