The utility model discloses a full -automatic intelligent sensor protection system of high temperature and high pressure optic fibre, including control system and sensing system, among the control system, light source and photoelectric detector are connected with fiber coupler through the optic fibre circulator respectively, fiber coupler is connected with a N wavelength division multiplexer respectively, a N sensor demodulation appearance is connected with the photoswitch through wavelength division multiplexer respectively for optical fiber sensor is waited to protect in the demodulation, microprocessor is connected with a photoelectric detector and a N photoswitch respectively, sensing system include N respectively with the optical fiber sensor one -to -one and the identical reserve optical fiber sensor that treat the protection, the signal power value that different sensors reflects back in design that this department is all crossed the light path structure is distinguished and isopened, basis for estimation when breaking down, and automatic switch -over to backup channel comes sensing and control section differentiation simultaneously, and sensing system adoption passive design under messenger's access silo guarantees that it can keep long term operation under high temperature and high pressure environment.