The invention provides an environment-friendly insecticide and a preparation method thereof, and relates to the technical field of pesticides. The environment-friendly insecticide is prepared from thefollowing traditional Chinese medicines in parts by weight: 3-5 parts of 
centipede, 3-12 parts of rhubarb, 6-14 parts of 
bletilla striata, 20-40 parts of cortex pseudolaricis, 3-5 parts of 
cantharides, 10-17 parts of Baixin and 30-43 parts of 
cinnamomum micranthum. The seven traditional Chinese medicines are organically proportioned by different preparation methods and finally mixed into the insecticide so that the insecticide has a very strong killing effect on various 
crop pests, does not generate 
drug antibodies in the pests, is suitable for long-term use, does not pollute the environment,does not generate 
pesticide residues on the surfaces of crops, by arranging 
cinnamomum micranthum in the environment-friendly insecticide, after the insecticide is sprayed to the surfaces of crops, the insecticide not only has a very good insecticidal effect, but also has a continuous 
insect expelling effect so that the crops can well grow, the insecticide has no harm to the health of farmers, does not pollute the atmospheric environment and is worthy of vigorous popularization.