The invention provides a distributed type fiber sensing device based on signal reusing perception and demodulation, comprising a laser, a first fiber coupler, a second fiber coupler, a light pulse modulator, a fiber annular device, an optical interface, a balance photoelectric detector, a low noise amplifier, a power divider, a first filter, a second filter, a frequency synthesizer, a mixer, a lowpass filter, a data collecting and processing module, and a computer. The feature that rayleigh scattering signals and Brillouin scattering signals can be generated at the same time is taken into consideration, and by means of the balance photoelectric detector, the rayleigh scattering signals and Brillouin scattering signals of the detection light pulse, generated in the detected fiber are simultaneously converted into radiofrequency signals of the corresponding frequency or frequency range. The rayleigh scattering signals and the Brillouin scattering signals are separated by means of the power divider and a band pass filter. The separated rayleigh scattering signals and the Brillouin scattering signals are accessed to the data collecting and processing module. The attenuation, vibration, and monitoring and displaying of the temperature and strain information of the fiber can be realized.