The invention discloses a method for electrosynthesis 1,3,4-oxadiazole-2 (3H)-ketone ramification from carbon dioxide, aromatic hydrazine and paraformaldehyde. According to the method, the carbon dioxide, the aromatic hydrazine and the paraformaldehyde serve as raw materials, the 1,3,4-oxadiazole-2 (3H)-ketone ramification is synthesized through electrochemistry by one step in a single compartment electrolytic tank; the carbon dioxide replaces phosgene or CO to serve as C1 raw material, cost is reduced, the effect of environmental benefits is achieved, and the double benefits of economy and environment protection are achieved; and a simple and valuable way for the synthesis of 1,3,4-oxadiazole-2 (3H)-ketone ramification and the utilization of the carbon dioxide is provided.