Abstract: With the rapid development of offshore wind power, submarine cables have been widely used. However, maintaining them poses significant challenges and involves lengthy cycles, resulting in considerable economic losses from even a single fault. Therefore, it is important to achieve accurate condition monitoring and early warning of submarine cables. In this paper, the differences between submarine cables and land cables are first analyzed in terms of length, structure, operation mode, and operating environment. The analysis shows that submarine cable accidents often occur in the cable, and the randomness of the fault location is high. Thus, distributed sensing is needed to monitor the submarine power cables. Next, methods for improving the distance and accuracy of distributed optical fiber sensing (DOFS) are reviewed and analyzed, such as topology improvement, pulse coding, noise reduction algorithms, and distributed amplification, and the main progress of DOFS in submarine cable condition monitoring is summarized. Then, the applications of different DOFS methods in the submarine cable monitoring projects are analyzed. Finally, the difficulties and opportunities in distributed optical fiber monitoring for submarine cable condition are summarized.