Aiming at the problem of optical network security protection, the anti-interception transmission technology of quantum noise random encryption(QNRC) physical layer is deeply studied from two aspects of physical layer security evaluation and experimental verification. Firstly, the development status of QNRC at home and abroad is introduced, and a set of general methods for physical layer security evaluation is summarized. Then, An experimental scheme of intensity shift keying quantum noise random encryption (ISK-QNRC) based on optical domain decryption is proposed. Aiming at the manufacturing process problems of high resolution and high sampling rate digital to analog converters in the scheme, a parallel ISK-QNRC scheme is proposed and verified. The results show that the scheme is safe and effective in information transmission. Finally, the typical application scenarios and development trends of QNRC technology are analyzed.