This type of sensor is manufactured by using the KF-FBT type fusion taper machine to uniformly pull the same single mode optical fiber. Double tapered section cascade type singles mode fiber. When the signal light passes through the concatenation fiber cone, the cladding mode is excited after passing through the first stage cone region. After a certain distance transmission, the second stage cone region interferes with the core mode. The change of the waveform is seen from the spectrometer. When the two cones are bent by 90, the article explores a double-cone-section cascading sensor that is easy to operate and easy to perform multi-point measurements from both theory and experiment. The spectral peak-to-valley contrast of the interference fringe is more obvious, and it can serve as a sensor head to test the ambient temperature. The sensor has a temperature sensitivity of 60 pm/°C.