In recent years, the management of dental caries has significantly shifted towards early detection and prevention, greatly enhancing treatment outcomes and reducing the need for invasive procedures. The article investigates the feasibility of using near-infrared diffuse reflectance imaging for early caries detection. The feasibility of using near-infrared diffuse reflectance imaging for early caries detection is investigated. Based on the theory of diffuse reflectance imaging in tissue optics and building upon previous research, we developed a near-infrared diffuse reflectance imaging system using 780nm wavelength LED illumination, named NIRCaries 780.To confirm the performance of NIRCaries 780,54 tooth surfaces were examined using both NIRCaries 780 and DIAGNOcam. Caries lesions were assessed by experienced dentists according to the ICDAS Ⅱ criteria. The performance of NIRCaries 780 was evaluated using the Spearman rank correlation coefficient. Compared to the ICDAS Ⅱ standard, the sensitivity, specificity, and accuracy of NIRCaries 780 were 0.806, 0.870, and 0.833, respectively. The sensitivity, specificity, and accuracy of DIAGNOcam were 0.871, 0.913, and 0.889, respectively. This technique, compared to DIAGNOcam, is simple to use, non-contact, and feasible for indicating early enamel caries. Future research will combine near-infrared diffuse reflectance imaging with automatic classification algorithms to provide technical means for home oral health care and caries prevention.