According to the fiber Bragg gratings optical sensing principle,a novel structure of fiber Bragg settlement sensors are developed,based on a cantilever beam and a metal diaphragm.The sensing characteristics are investigated.In the experiment,water level differences to are used simulate foundation settlement.The experimental results indicate that sensitivity of -2.11pm/mm and good linearity of higher than 0.999 can be obtained.By changing the thickness and the effective length of cantilever beam,the measurement range and sensitivity of the sensor can be optimized to meet various applications.From the results,it is known that the sensor will play an important role in bridges,railways and other foundation settlement monitoring.