The invention belongs to the technical field of animal senile dementia models, and particularly relates to a method for establishing an animal senile dementia model. The animal model building processlasts for 30 days, a metal compound is injected into the animal abdominal cavity within the first six days, D-galactose is injected in the seventh day, a metal compound is injected into the animal abdominal cavity in the eighth day, and D-galactose is injected into the animal abdominal cavity from the ninth day to the fourteenth day every day; meanwhile, an animal is placed in a power-frequency magnetic field environment for radiation treatment from the eighth day to the fourteenth day, and metal compound, D-galactose and power-frequency magnetic field environment radiation treatment is conducted simultaneously from the fifteenth day to the twenty-first day, and a metal compound is injected into the animal abdominal cavity from the twenty-second day to the thirtieth day. According to the method, the stable memory impairment rat model is established, the reproducibility is good, the senile dementia model caused by composite factors is simulated, the one-sidedness of a single-factor induced impairment model is avoided, aging is also accelerated, the time for constructing the model is shortened, and the cost is reduced.