Evaluate the Safety and Efficacy of AD-35 Tablet in Subjects With Mild to Moderate Alzheimer's Disease

Inclusion Criteria: * Men and women, 50-75 years of age. * Formal education of five or more years. * Diagnosed of probable AD in accordance with the NINCDS/ADRDA criteria (2011). * Mild or moderate AD subjects: MMSE Score of 15-26 and CDR Score ≥ 0.5 (CDR memory score ≥ 0.5). * Subjects must have a brain magnetic resonance imaging (MRI) scan that is consistent with a clinical diagnosis of probable AD. Brain atrophy and medial temporal lobe atrophy visual assessment scale MTA grading \>2 points. Mild white matter degeneration may occur, but Fazekas less than or equal to 2 points and supratentorial lacunar infarction lesions less than or equal to 3 points. * The total score of modified Hachinski ischemia scale (MHIS) ≤ 4. * Hamilton depression scale (HAMD) has a total score ≤ 17. Exclusion Criteria: * Visual, hearing and verbal communication of subjects cannot meet the needs of cognitive function evaluation. * Inability to tolerate MRI procedures or contraindication to MRI, (such as implanted in the body, MRI incompatible pacemakers, implantable cardioverter defibrillators, cochlear implants, aneurysm clips, implanted injection pump, implanted nerve stimulator, metallic splinters in the eye, other magnetic, electrical and other metal implants) \[note\], or any other situation, in the judgment of the Investigator, is not suitable for magnetic resonance imaging (MRI). * The investigators believe that other severe or unstable conditions may interfere with the cognitive evaluation in clinical trials. * Dementia caused by other reasons: vascular dementia, central nervous system infection, endocrine system diseases (such as thyroid disease, parathyroid gland disease) and other reasons.