The invention discloses an exact locating method for fault points of a submarine cable. The exact locating method for the fault points of the submarine cable comprises the following steps of: realizing real time online monitoring of the submarine cable by utilizing BOTDR (brillouin optical time domain reflectometer) or BOTDA (brilouin optical time domain analysis); carrying out combined analysis by utilizing strain/temperature information, a submarine topography and geologic structure and construction details carried by a brillouin scattering signal; and extracting feature points, and establishing a database so as to largely improve the location precision. After the database is established, complex data query and calculation operations can be saved as long as a submarine cable has failure, thus the fault position can be quickly and exactly located, the submarine cable can be repaired and the labors and materials are largely saved.