A hybrid single beam spectrum α=αb1+(1－α)b2=α0e－Kb1+(1－α)0e－Kb2 is introduced as the combination of two single beam spectra b1 and b2 from the same sample but with different pathlengths (b1 and b2), where α(0＜α＜1) is the hybrid coefficient. The intensity of hybrid spectrum α can be controlled easily to the desired point by simply choosing an appropriate α. The experimental results showed that hybrid spectrum α is very nearly identical to b=0e－K(b2－αb2+αbb) under appropriate conditions, namely α≈b, where b is the single beam spectrum of the real sample with the pathlength of b2-αb2+αb1. Therefore, the desired single beam spectrum b can be obtained easily by choosing α and we no longer need to prepare IR sample with the thickness of b. Hybrid spectrum method shows valuable potential in application of eliminating background interference.