The invention belongs to the technical field of medicinal chemistry, in particular to N-(3,5-dimethyladamantane-1-yl)-N'-substituted phenylurea compounds as well as preparation methods and application thereof. The compounds have the structure shown in the formula I. The compounds are proved that the compounds can improve the image recognition memory, the working and learning memory, the spatial learning and memory ability of model rats and has good anti-alzheimer effects by the new object discrimination experiments, Y-maze experiments, positioning navigation and space exploration experiments in mats. The formula I is shown in the description.