Distributed optical fiber sensors based on Rayleigh backscatter is sensitive to strain and temperature with high resolution. In the matter of strain measurement method, differences between distributed optical fiber sensors and strain gauges were analyzed and compared. Unidirectional tensile tests of aluminum bar were conducted to contrast data measured by distributed optical fiber sensors and strain gauges, on the aspects of accuracy, linearity, and repeatability. Advantages of distributed optical fiber sensors in strain measurement were also analyzed through bending test on unequalthickness cantilever beam. And strain field on the surface of structure is reconstructed by means of strain data measured by distributed optical fiber sensors.