A rate matching method, comprising: performing, by a sending apparatus, encoding of information bits by using a polar code to obtain a first encoded sequence whose bit length is N, wherein a sequence number of a polarization channel ranges from 0 to is the mother code length and has a value equal to an integral power of 2; determining, by the sending apparatus, P1 to-be-punctured bit positions, and performing puncturing at the P1 bit positions in the first encoded sequence to obtain rate-matched encoded bits, wherein the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, P T1 to 3N/8-1, or N/2 to 5N/8-1, P T1 is a threshold of a quantity of the to-be-punctured bit positions, and P T1 ≤N/4; and sending the rate-matched encoded bits, wherein: if PI is less than or equal to P T1, the to-be-punctured bit positions are the bit positions corresponding to the polarization channels 0 to P T1 -1, wherein if P1 is greater than P T1, the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels that have lowest reliability among polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1; or the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels comprised in K1 groups that have lowest reliability among S1 groups of polarization channels comprising polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1; or the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels comprised in K2 groups that have a lowest code weight among S2 groups of polarization channels comprising polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1. performing, by a sending apparatus, encoding of information bits by using a polar code to obtain a first encoded sequence whose bit length is N, wherein a sequence number of a polarization channel ranges from 0 to is the mother code length and has a value equal to an integral power of 2; determining, by the sending apparatus, P1 to-be-punctured bit positions, and performing puncturing at the P1 bit positions in the first encoded sequence to obtain rate-matched encoded bits, wherein the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, P T1 to 3N/8-1, or N/2 to 5N/8-1, P T1 is a threshold of a quantity of the to-be-punctured bit positions, and P T1 ≤N/4; and sending the rate-matched encoded bits, wherein: if PI is less than or equal to P T1, the to-be-punctured bit positions are the bit positions corresponding to the polarization channels 0 to P T1 -1, wherein if P1 is greater than P T1, the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels that have lowest reliability among polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1; or the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels comprised in K1 groups that have lowest reliability among S1 groups of polarization channels comprising polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1; or the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels comprised in K2 groups that have a lowest code weight among S2 groups of polarization channels comprising polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1. if PI is less than or equal to P T1, the to-be-punctured bit positions are the bit positions corresponding to the polarization channels 0 to P T1 -1, wherein if P1 is greater than P T1, the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels that have lowest reliability among polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1; or the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels comprised in K1 groups that have lowest reliability among S1 groups of polarization channels comprising polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1; or the P1 to-be-punctured bit positions are bit positions corresponding to polarization channels 0 to P T1 -1, and bit positions corresponding to P1-P T1 polarization channels comprised in K2 groups that have a lowest code weight among S2 groups of polarization channels comprising polarization channels P T1 to 3N/8-1 or N/2 to 5N/8-1.