The Optical Low Coherence Reflectometry (OLCR) is proposed to solve a problem that the reflective spectrum of a Fiber Bragg Grating (FBG) can be out of a shape under non-uniform strain loading. Based on a Michelson interferometer,an OLCR system is set to measure the pulse response of the FBG,and the time domain pulse response of FBG is converted into the frequency domain reflection response by Fourier transform. Then the spatial response of FBG relevant to Bragg wavelength is reconstructed with a lay peeling technology. Thus, the non-uniform strain distribution is calculated from the sensing model of FBG. With an effective system, the OLCR is illustrated in detail. An experiment of composite delamination in modeⅠis conducted, and the non-uniform strain distribution is obtained with reliability. The axial measurement resolution in the FBG is 13.2 mm, and the scanning precision of the system reaches 100 nm. The OLCR system demonstrates an excellent performance in demodulating the FBG non-uniform strain sensing, which shows that the system has a promising application prospect.