A method of introducing a binary optical lens into spectral confocal micro-spacing measurement is proposed to address the problems that the dispersion linearity of a conventional dispersion lens is difficult to ensure absolute linearity and that the measurement range is narrow, meanwhile minimizing spherical aberration, particularly the axial spherical aberration which has the greatest influence on measurement. In the proposed method, the dispersion of the binary optical lens is only related to the wavelength of the incident light and it is strictly inversely proportional to the wavelength of the incident light. Binary optical lenses do not exhibit spherical aberration problems and can also compensate for the unknown chromatic aberrations of other optical components in the calibration measurement system. In the experiment, a spectrum in the range of 510--690 nm is selected, and the spectral information is received by a spectrometer with a 0.5-nm resolution. Furthermore, the measurement range of this method is 13.95 mm, the measurement error is 0.6 μm, and the recording spacing with respect to the optical disc is measured to verify the effectiveness of the proposed method.