The invention provides an
optical fiber sensing method which takes a full-scale distribution type and has locally and highly precise collineation, and a
system of the
optical fiber sensing method comprises the parts of a Brillouin sensing
demodulation device, a
fiber grating demodulation device, an
optical switch (or a coupler) and an FRP-FBG-OF sensing probe, etc. One or a plurality of
fiber gratings are written onto an ordinary single mode
fiber with arbitrary length and made into the sensing probe through the encapsulation of FRP, and the sampling
optical switch or the coupler is respectively connected with the fiber
grating demodulation device and a Brillouin
distributed testing system, thus forming an intelligent sensing
monitoring system which implements the large-scale, full-distributed and locally and highly precise testing of structural damage, achieves the full-scale damage positioning and quantitative testing of important projects and the mutual checking effect, and provides complete, direct and reliable information for
structural safety evaluation. The
optical fiber sensing method is especially applicable to structural damage monitored objects which are characterized by wide distribution range, long distance and concealed position, etc., and has the advantages of compact
system, low cost, strong
operability, good stability and durability and reliable result, etc.