The invention relates to a method for designing a puncturing device based on key control in order to solve the problem that a conventional Turbo code puncturing device does not have code rate self-adaption and encryption functions. According to the method, an interleaver is associated with the puncturing device, firstly, the length of the interleaver is set as N, S is a natural number sequence with the length N, a random natural number arrangement S1 with the length N is generated by a Key, namely, S1=f (S, Key), the f refers to a random function, secondly, the overall bit number P needing to be deleted is calculated according to a code rate R, finally, a code bit sequence is punctured, code bits of sequence numbers smaller than or equal to P after mapping f in the S are deleted, and code stream is outputted. When in puncturing release, the sequence numbers smaller than or equal to the P after mapping f in the S are positioned at 0, the rest code bits are determined by input N-P long sequences, and the code stream with the length N can be released from puncturing.