A reflective fiber-optic angular displacement sensor based on structure of three probes with equal transverse space is designed to achieve large range and high sensitivity angle displacement measurement with intensity compensation. The mechanism of this sensor is analyzed theoretically

and the modulating function is gained based on the mathematical model. Effects of the distance h between end face of fiber probe and reflective surface

and effect of spin radius R of probe on sensing property is analyzed through simulation. Sensing property of sensor with single receiving fiber angular displacement sensor is verified by experiments. The results indicate that linearity between output light intensity and angular displacement is desirable. The larger the distance h is

the higher sensitivity the sensor possesses. On the other side

the smaller the spin radius R is

the lower the sensitivity is

at the same time

the sensing range is relatively larger.