A rate matching method for a Polar code, comprising: concatenating K information bits and (N-K) frozen bits to generate a bit sequence of N bits, and encoding the bit sequence of N bits by means of a Polar code encoder with a generator matrix of size N×N to generate an initial bit sequence { S 0, S 1,..., S N -1} of N bits, wherein K and N are both positive integers and K is less than or equal to N; selecting bits from the initial bit sequence { S 0, S 1,..., S N -1} in a non-repeated manner and writing the bits into a circular buffer; and sequentially selecting a bit sequence of a specified length from a predefined starting position in a bit sequence in the circular buffer, wherein the bit sequence of the specified length is taken as a bit sequence to be transmitted, wherein the writing the bits into the circular buffer comprises writing the bits into the circular buffer based on a predefined rule, wherein the predefined rule is determined by a one-to-one mapping interleaving function f(n) generated according to a data characteristic of the Polar code, wherein n=0, 1,..., N-1, f(n)=0, 1,..., N-1, n is a bit position index of a bit in the initial bit sequence, and f(n) is a position index of the bit in the circular buffer, and wherein the predefined starting position is selected in the following manner: when the code rate of the Polar encoding is less than or equal to a predefined threshold, a position of P 0 =N-M in the circular buffer is taken as the predefined starting position, wherein P 0 represents a position index of the bit sequence in the circular buffer, M is the specified a length of the bit sequence to be transmitted, and N is a length of the initial bit sequence. concatenating K information bits and (N-K) frozen bits to generate a bit sequence of N bits, and encoding the bit sequence of N bits by means of a Polar code encoder with a generator matrix of size N×N to generate an initial bit sequence { S 0, S 1,..., S N -1} of N bits, wherein K and N are both positive integers and K is less than or equal to N; selecting bits from the initial bit sequence { S 0, S 1,..., S N -1} in a non-repeated manner and writing the bits into a circular buffer; and sequentially selecting a bit sequence of a specified length from a predefined starting position in a bit sequence in the circular buffer, wherein the bit sequence of the specified length is taken as a bit sequence to be transmitted, wherein the writing the bits into the circular buffer comprises writing the bits into the circular buffer based on a predefined rule, wherein the predefined rule is determined by a one-to-one mapping interleaving function f(n) generated according to a data characteristic of the Polar code, wherein n=0, 1,..., N-1, f(n)=0, 1,..., N-1, n is a bit position index of a bit in the initial bit sequence, and f(n) is a position index of the bit in the circular buffer, and wherein the predefined starting position is selected in the following manner: when the code rate of the Polar encoding is less than or equal to a predefined threshold, a position of P 0 =N-M in the circular buffer is taken as the predefined starting position, wherein P 0 represents a position index of the bit sequence in the circular buffer, M is the specified a length of the bit sequence to be transmitted, and N is a length of the initial bit sequence.