The invention relates to a preparation method of an in vivo glycation level-improving dementia animal model. By dosing animals with D-ribose, the invention provides an in vivo glycation level-improving dementia animal model and its preparation method. The animal model provided in the invention has the characteristics of normal blood sugar level, enhanced glycation level, and damaged spatial learning and memory ability. At the same time, the method disclosed in the invention has the advantages of simplicity, practicability, easy control, stability and good reproducibility, low model making cost as well as short model making cycle. The model making method provided in the invention can be used for qualitative and quantitative analysis, pathomorphological contrastive analysis, and also can be used for statistical treatment and analysis. Also, the method can be used for studying in vivo glycation level enhancement-caused related diseases and the pathogenesis of neurodegenerative diseases, as well as studying and evaluating related disease treatment methods.