Provided is an insecticide and a preparation method thereof. The insecticide consists of the following components in parts by mass: 6-8 parts of chlorhexidine, 7-9 parts of camphor oil, 4-6 parts of an antioxidant, 6-10 parts of pyrethrin, 5-7 parts of Herba Geranii, 5-7 parts of pine needle extract, 4-6 parts of ethyl acetate, 6-8 parts of sodium hexametaphosphate, 2-4 parts of piperonyl butoxide, 4-6 parts of stearic acid, 6-8 parts of atrazine, and 20-40 parts of water. The components of the insecticide are not poisonous, and not harmful to the human body.
