A coding method, a wireless device, and a chip are described. A coding method may include obtaining, based on a sequence whose length is 2n′, a mother code sequence used for coding, where the sequence whose length is 2n′ includes 2n′ sequence numbers, a length of the mother code sequence is 2n, the mother code sequence includes 2n sequence numbers, the 2n sequence numbers are some or all of the 2n′ sequence numbers, n′ is a natural number, and n is a natural number less than or equal to n′. The method may also include coding an input to-be-coded bit by using the mother code sequence. According to this method, a system may store one or more long sequences, and then obtain a required mother code sequence from one of the long sequences according to a coding requirement, thereby reducing storage overheads of the system.