Abstract: The dual-energy X-ray bone densitometer system is the "gold standard" for current X-ray bone density measurement technology, which holds unique advantages such as high measurement accuracy, little time cost and low dosage. In this paper, semiconductor CdZnTe detector module was used to build a bone mineral density energy spectrum measurement platform operated by semiconductor photon. Based on the characteristics of CdZnTe semiconductor detector, we performed the moving least square algorithm on the high-low energy fitting and correction of different materials. The moving least-squares algorithm changes the degree influenced by the surrounding nodes of the target data point through the weight function, which can make the fitting direction of the data point more flexible. The research analyzed the data processing flow of the moving least- squares algorithm performed on the dual-energy X-ray bone density measurement value, and completed the bone density measurement experiment operated by the high-low energy fitting and correction algorithm based on the moving least-squares. According to the experimental results, in this paper we designed and intended to achieve that the dual-energy fitting technology of bone density based on the moving least-squares algorithm can achieve better fitting error accuracy in practical applications, the average fitting error of the detector pixel unit under high-energy conditions is 0.032% while the average fitting error under low-energy conditions is 0.036%. Further data analysis showed that the difference of fitting error between the edge pixels and the center pixels under high and low energy conditions was only 0.012% and 0.011% respectively. This algorithm can effectively improve the bone mineral density measurement accuracy of semiconductor detectors, and reduce the influence of errors caused by the the pixels at the edge of the detector. The photon-counting detectors have an improving effect on the bone density mineral diagnosis influenced by pixel differnce of linear array or plane array photon counting semiconductor detectors.