In absolute distance measurement, interferometric methods are severely affected by the uneven distribution of refractive index of air along the optical path with turbulence. To solve this problem, a multi-wavelength interferometric method for absolute distance measurement is presented, which can compensate for the refractive index of air in real time. Instead of monitoring the real-time environmental parameters, this method based on the excess fractions method can obtain the geometric length by using the relationship between the refractive index of different wavelengths provided by the A coefficient. A theoretical analysis based on the excess fractions method is presented, and a numerical simulation with 594.1 nm, 611.9 nm and 632.8 nm wavelengths is conducted on computer. The result shows the relationship between the Unambiguous Measurement Range (UMR) and the required fringe fraction resolution under this wavelength combination.