Objective To explore the clinical value of gemstone spectral CT imaging technique in preoperative staging of esophageal cancer. Methods The imaging data of 85 cases of patients with esophageal cancer which confirmed by operation and pathology were collected. According to pathological results, they were divided into low differentiation group (n=23), moderate differentiation group (n=24) and high differentiation group (n=17). Before operation, they were given chest plain scan and dual-phase enhanced scanning by using GSI mode, and the diagnostic value was analyzed. Results There was no significant difference in the lesion location and tumor size among the three groups (P>0.05). At 40-100 keV single energy, the CT values of lung cancer in low, medium and high differentiation groups were in turn from high to low(P<0.05). The iodine concentration and NIC in low differentiation group were significantly higher than those in moderate and high differentiation groups (P<0.05), and there was no significant difference in the water concentration among the three groups (P>0.05). The ROC curves for iodine concentration and NIC of low, moderate and high differentiation groups showed that the area under curve (AUC) of iodine concentration was 0.655, and the AUC of NIC was 0.826. The sensitivity and specificity of iodine concentration for the diagnosis of lowly, moderately and highly differentiated esophageal cancer were 56.52% and 53.66% respectively, and the two indexes of arterial phase NIC were 73.91% and 78.05%. Conclusion In gemstone energy spectrum CT imaging, NIC in arterial phase has high diagnostic value in differentiating low-to medium-to High-differentiated cancers, and has potential to be used in preoperative pathological grading of esophageal cancer. NIC