Low density parity check （LDPC） code hopping can improve the security and reliability of information transmission through error control coding based on the hopping check matrix at the physical layer. Quasi-cyclic low density parity check code （QC-LDPC） is widely used because of its good error correction performance and easy engineering implementation. This paper proposes a QC-LDPC code hopping design method. Firstly two kinds of subgroups in finite field are used to design the hop-basis matrix， and then the check matrix of the hashed basis matrix is masked by the protograph-based external information transfer （PEXIT）， so that the hop matrix has a unified architecture and a fast coding structure， which is easy to implement in engineering. Simulation and analysis show that the designed QC-LDPC codehopping has a huge code hopping set and good error-correcting performance. The number of LDPC codes in a code hopping set can be up to 10³⁴. With the increase of code length， the number of LDPC codes in a code hopping set increases exponentially， and the average performance of LDPC codes is comparable to that of many protocols. It can be used to improve the reliability and security of the communication system.