Embodiments of this application disclose a example polar code encoding methods, example polar code decoding methods, and example apparatuses thereof. One example method in embodiments of this application includes generating an input vector, where the input vector includes T subblocks, a first information bit of a first subblock is obtained by replicating a second information bit of a second subblock, the first subblock and the second subblock are subblocks of the T subblocks, a sequence number of the first subblock is after a sequence number of the second subblock, and T is an integer greater than or equal to 2. Polar encoding can then be performed on the input vector to obtain an encoded bit.