The distributed optical fiber sensing technology is overviewed,which is based on Raman scattering light theory.Basic operation principle,structure,system characteristics and signal processing are discussed.This structure and method of the signal processing possess of certain spatial resolution,hence will ensure the practicability of system. The distributed optical fiber sensing technology is overviewed, which is based on Raman scattering light theory. Basic operation principle, structure, system characteristics and signal processing are discussed. This structure and method of the signal processing possess certain certain spatial resolution, hence will ensure the practicability of system.