In this paper a convolution form of atomic spectral profiles having isotope shifts transformed by a scanning planar Fabry-Perot interferometer (SFPI) is presented. The method and corresponding code of deoonvolution of the spectral line profile obtained by SFPI are proposed and are characterized by using the nine-parameter Gauss iteration of the least squares fitting for the first time. By this method the magnitude of isotope shift, isotope abundance ratio, Lorentz width and Doppler width of the spectral profile can be deduced.