This application provides a polar code encoding method and apparatus, a polar code decoding method and apparatus, and a device. The encoding method includes: sequentially configuring, by a sending device, information bits and first check bits on subchannels in a first subchannel set, and configuring frozen bits on subchannels in a second subchannel set, where the subchannels in the first subchannel set are sorted according to a natural order of serial numbers of the subchannels, and reliability of the subchannels in the first subchannel set is higher than reliability of the subchannels in the second subchannel set; and performing, by the sending device, polarization encoding on bits on the subchannels to obtain an encoded sequence. According to this application, the information bits and the first check bits can be configured on the subchannels that are sorted according to a natural order, without a need to skip one or more subchannels during configuration. In this way, encoding efficiency and decoding efficiency are improved.