Referring to the problems in using low-resolution charge coupled device (CCD) to measure fiber Bragg grating (FBG) peak wavelength, a high-precision method for determining the FBG peak wavelength shift by matching basis function based on the FBG actual reflection and sampling data measured by CCD is proposed. The effectiveness and feasibility of the new method are studied theoretically and experimentally. It is proved that compared with fitting sampling data by specific functions, the matching method based on FBG actual reflection spectrum can determine FBG peak wavelength shift more accurately. In the case of few sampling data and low resolution of CCD measurement, the high-precision determination of FBG peak wavelength shift is achieved. The accuracy of demodulation of FBG peak wavelength shift using low-cost CCD in the practical applications is improved effectively.