Abstract: K-edge filter is often used in dual-energy X-ray bone densitometry. However, its use with multi-energy bin photon counting detector without Ce and dual-energy with Ce in bone densitometry requires further studies and comparisons. We chose to optimize the spectrum of broad X-ray by using the K-edge characteristic of cerium (Ce) of rare earth material, so as to obtain the dual-energy spectrum. A corresponding energy-threshold calibration method is proposed for dual-energy spectrum in this case, hoping to improve the accuracy of material decomposition in bone densitometry. In this paper, we did a comparison experiment between the triple/dual-energy decomposition without Ce and the dual-energy decomposition after Ce filtration. The experimental results show that the accuracy of the triple-energy decomposition is higher than that of the dual-energy decomposition when without the Ce filtration, and the accuracy of the dual energy decomposition after the addition of Ce filtration is better than that of all the non-Ce filtration obsolete.