Dual-energy X-ray imaging system combining the high and low transmission signal to serve the method of object classification(calculate R related with effective atomic number) at present.But(object's) thickness has great effect on dual-energy transmission imaging.Videlicet

(object's) thickness influences the veracity of object classification.This paper put forward an improving numerical optimized method by the ratio of two transmission signal to eliminate the effect of the thickness

with optimized area absorption coefficient transmission signal to replace the transmission signal.This method can weaken the effect of(object's) thickness on R

decrease the probability of inaccuracy and improve the veracity of classification by analyzing and evaluating experimental data.