Mach-Zehnder interference type all-fiber bend sensing device

The invention relates to an optical fiber sensing technology, and discloses a Mach-Zehnder interference type all-fiber bend sensing device. The device is provided with a pumping laser which is connected with a wavelength division multiplexer through a connecting optical fiber, two ports of the wavelength division multiplexer are connected with an erbium-doped fiber and a polarization controller through connecting optical fibers respectively, the erbium-doped fiber is connected with one end of an optical isolator, the other end of the optical isolator is connected with the independent end of a 1*2 type optical fiber coupler through a connecting optical fiber, and the other end of the 1*2 type optical fiber coupler is provided with two ports which are connected with a tapered optical fiber filter and an optical fiber spectrometer through connecting optical fibers respectively; the other end of the polarization controller is connected with the tapered optical fiber filter through a connecting optical fiber. The