One encryption of fiber optic communication data cannot cause all data to appear in a scrambled state, and data security is still relatively poor. Therefore, a fiber optic communication data scrambling encryption method based on discrete chaotic mapping is studied. Wavelet decomposition is performed on the original fiber optic communi- cation data, and all wavelet coefficients are scrambled based on the Knight’s Patrol Theory and the characteristics of wavelet subbands to complete the scrambling of fiber optic communication data. By constructing a chaotic sequence u- sing discrete chaotic mapping and Sine mapping, the data is encrypted once using the chaotic sequence, and the fiber optic communication data is encrypted twice using a position matrix to achieve scrambled encryption of fiber optic com- munication data. The experimental results show that the proposed method can effectively improve the security of fiber optic communication data, with good data encryption and confidentiality performance.