This application provides a polar code encoding and decoding method and apparatus and a device. An example 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 performing polarization encoding on bits on the subchannels to obtain an encoded sequence. In this way, encoding efficiency and decoding efficiency are improved.