In calculation of the energy levels of FA centers in KCl crystals, the difference of the ability of binding an electron between host and doping ions affects the distribution of binding electron cloud of FA center. It is the basis for choosing a calculation method of electron energy level ef FA centers. The energy level of three kinds of typical doping: Li:KCl:FA(II); Cu:KCl:FA (III), T1:KCI:FA(III) have been caloulated in this paper. The deviations are less than 5% as compared with experimental values.