A novel all-fiber inline Michelson interferometer by using CO2 laser pulses to introduce edge-deformation in single mode fiber is demonstrated.The simple fabrication technique can couple a part of light from the core mode into the fiber cladding,and the coupling mechanism is analyzed theoretically.Based on the larger thermal optical coefficient difference between the core mode and the cladding modes,the interferometer can be used for high temperature measurement.The experimental results show that the temperature sensitivity of the sensor could be-0.093 7 nm/℃,and it exhibits good linearity and repetition within 800 ℃.Such an all-fiber inline Michelson interferometer with simple fabrication,good stability,small size and high sensitivity may find potential applications in national defense and civilian industry.