Provided is a rate matching method and device for a Polar code. The method includes: 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 {S0, S1, . . . , SN−1} of bits, where K and N are both positive integers and K is less than or equal to N; dividing a circular buffer into q parts, selecting bits from the initial bit sequence {S0, S1, . . . , SN−1} in a non-repeated manner, and writing the bits into the q parts of the circular buffer according to a predefined rule, where q=1, 2, 3 or 4; and sequentially selecting a bit sequence of a specified length from a predefined starting position in a bit sequence in the circular buffer and taking the bit sequence of the specified length as a bit sequence to be transmitted.