A method for performing polar coding is disclosed in the application. A data block is segmented into a plurality of first blocks. Difference in bit length between any two first blocks is not more than one bit. For each first block, one or more consecutive padding bits is added to obtain a second block of a bit length K if the bit length of the first block is less than K, so as to obtain a plurality of second blocks corresponding to the first blocks. N-K consecutive bits are added to each of the second blocks to obtain a plurality of third blocks. Polar encoding is performed on the third blocks.