This application discloses a communication method that comprises obtaining first data, where the length of the first data is A; compressing the first data into second data, where the length of the second data is C; and generating third data based on the second data, where the third data includes the second data and (T−C+p) alignment bits. T is a threshold in the J thresholds that is greater than or equal to C and the closest to C. The J thresholds correspond to A and are greater than 0, with J being a positive integer greater than or equal to 2. p is a quantity of auxiliary check bits and is an integer greater than or equal to 0. The communication method further comprises performing channel encoding on the third data to obtain fourth data and sending the fourth data.