Based on the advantages of fiber Bragg Grating (FBG) sensor, such as light weight, good anti-interference and durability, this paper proposes applying FBG sensors to helicopter rotor blade load measurement. The research includes static and dynamic calibration of surface-bonded FBG sensors on an equal strength beam, high-reliability fusion of FBG sensors with the blade surface, and ground rotor platform test. The test results show that the strain sensitivity coefficient of the FBG sensor is 1.28. The surface-bonded FBG sensor meets the requirements of fatigue and creep characteristics. The peak-to-peak value measured by the FBG sensor is 1.8% larger than that measured by the resistance strain gauge, which proves that it can be used for strain measurement of helicopter blades in complex working environment for a long time. At 0.1R, the mean differences in flapping and lagging loads measured by FBG sensors and resistance strain gauges were up to 7.7%. The test results at other blade sections showed good consistency with simulation analysis. These findings demonstrate that using FBG sensors for measuring rotor blade section loads is reliable and has engineering application value.