An all-fiber Mach-Zehnder interferometer sensor based on Bitaper-LPFG-Bitaper structure is proposed and fabricated, and the temperature sensing characteristic of the sensor is analyzed. The experimental results show that the sensor presents different characteristics at the different resonance wavelengths by changing the distance between the two bitapers, for the fixed structures parameters of the two bitapers and LPFG. The sensitivity of the sensor reduces with the increasing distance between the two bitapers at the shorter resonance wavelength, but increases at the longer resonance wavelength. When the length of the sensor is 16.5 cm, its sensitivity reaches 0.102 06 nm/℃ around 1 680 nm. The research work is important for the optimization design of temperature sensor consisting of bitaper and LPFG.