The invention discloses a transdermal medicament delivery system containing a donepezil compound, a transdermal preparation and a preparation method. The transdermal medicament delivery system comprises the following components in percentage by weight: 0.1 to 50 percent of donepezil or acid radical salt thereof, 1 to 95 percent of skeleton polymer, 0.1 to 60 percent of transdermal penetration enhancer, 0 to 10 percent of cross linker, 0.5 to 60 percent of humectant, 0.02 to 10 percent of bacteriostatic agent, 0.02 to 30 percent of pH regulator and 0 to 90 percent of solvent. The system is used for treating light, medium and severe senile dementia, can maintain long-time stable medicament delivery of at least 3 days, has better performance, is convenient for medicament delivery, and can reduce the administration frequency and increase the compliance of patients; and meanwhile, the transdermal path avoids first-pass effect on gastrointestinal tracts and liver due to oral administration of medicaments, and the system has higher bioavailability and obvious advantages in medicinal application.