This application discloses a polar code segment encoding method, including: determining, based on a length of to-be-encoded information bits and a code rate, a code length N after encoding; determining, based on N , a minimum segment code length, and a maximum segment code length, a reserved segment quantity of each type of segments in segments of b - a +1 types of segment code lengths and a reserved code length corresponding to N , where the minimum segment code length is 2^ a , and the maximum segment code length is 2^ b ; determining a segment quantity of each type of segments based on N , the reserved code length, a segment code length of each type of segments, and the reserved segment quantity of each type of segments, where N corresponds to S segments, and a segment code length of an i th segment in the S segments is greater than or equal to a segment code length of an (i+1) th segment in the S segments; determining target information bit lengths of the S segments based on the code rate and segment code lengths of the S segments; and performing polar code encoding on the to-be-encoded information bits based on the target information bit lengths of the S segments. Through implementation of this application, performance of a low-power communication system can be effectively improved when a delay limit of decoding and reporting is met.