Embodiments of this application disclose a communication method and a communications apparatus. The method includes: determining an encoding matrix type of a first sequence based on a modulation and encoding scheme (MCS) index, where the first sequence is obtained after code block segmentation is performed on a second sequence, a length of the second sequence is related to the MCS index, and a length of the first sequence is less than or equal to a first threshold; and encoding the first sequence based on the encoding matrix associated with the encoding matrix type. According to the application, the encoding matrix type can be properly selected for encoding.