The invention discloses a synthesis method and application of a multi-target A beta oligomerization inhibitor. The synthesis method comprises the following steps: (1) taking bromaniline or derivatives thereof and (1-benzylpiperidine-4-yl)methylamine or derivatives thereof as starting raw materials, and carrying out Suzuki coupling reaction for preparing an intermediate II; (2) taking the intermediate II and 1,3-dibromopropane or other analogues as raw materials, and carrying out SN2 reaction for preparing an intermediate III with an alkyl chain; and (3) taking the intermediate III with the alkyl chain and imidazole or derivatives thereof as raw materials, and carrying out SN2 reaction for preparing the target product multi-target A beta oligomerization inhibitor. The synthesis method disclosed by the invention is simple and reliable in route, high in yield and more suitable for large-scale preparation. The multi-target A beta oligomerization inhibitor is applied to preparation of an A beta oligomerization inhibitor anti-AD medicine, a glutaminyl cyclase inhibitor anti-AD medicine and an acetylcholin esterase inhibitor anti-AD medicine and can be applied to kits of A beta oligomerization, glutaminyl cyclase and acetylcholin esterase.