This application provides an encoding method and apparatus. The method includes: performing CRC encoding on A to-be-encoded information bits, to obtain a first bit sequence, where the first bit sequence includes L CRC bits and A information bits; performing an interleaving operation on the first bit sequence, to obtain a second bit sequence, where a first interleaving sequence used for the interleaving operation is obtained based on a system-supported maximum-length interleaving sequence and a preset rule, and a length of the first interleaving sequence is equal to A + L ; or a second interleaving sequence used for the interleaving operation is the maximum-length interleaving sequence, a length of the second interleaving sequence is equal to K max + L , and K max is a maximum information bit quantity corresponding to the maximum-length interleaving sequence; and performing polar encoding on the second bit sequence. Therefore, during distributed CRC encoding, when an information bit quantity is less than the maximum information bit quantity, an interleaving sequence required for completing an interleaving process is obtained based on the system-supported maximum-length interleaving sequence.