The disclosure provides a method and a device in a communication node for wireless communications. The communication node first receives first information and then receives a first radio signal; only X1 bit(s) in a first bit block is(are) used for generating the first radio signal, the first bit block is obtained as an output of channel coding of a first code block, the first code block includes a positive integer number of bit(s), and the first bit block includes a positive integer number of bit(s); when channel decoding fails, at least X2 bit(s) in the first bit block can be used for decoding of the first code block with combining, the first information is used for determining the X2 bit(s), and the X2 is a positive integer. The disclosure reduces requirements on a buffer and reduces complexity.