Based on the principle of OFDR distributed optical fiber measurement technology,the accuracy of strain measurement by using polyimide fiber under different wiring modes on the surface of equal strength beam is studied.The strain distribution on the surface of the beam was measured under the conditions of the polyimide fiber bonding parallel to,perpendicular to the length direction,at an angle of 45° and wound into a circle with a diameter of 50 mm respectively.The measured results were compared with the strain gauges and theoretical values,and the measurement results of the axial strain distribution of the optical fiber under nonaxial stress and bending are studied,and the error is less than 1%.The experimental results show that the optical fiber technology based on the principle of OFDR can achieve continuous and accurate measurement of structural surface strain.