The invention discloses a lemon insecticide. The lemon insecticide comprises, by weight, 40-60 parts of radix bupleuri, 20-40 parts of flos daturae, 10-20 parts of cortex phellodendri, 5-15 parts of phytolacca acinosa, 10-20 parts of rhizoma acori tatarinowii, 5-15 parts of flos carthami and 3-12 parts of radix paeoniae alba. The lemon insecticide has the advantages that the lemon insecticide is a botanical insecticide, does not contain optional chemical pesticide components, is low in toxicity for human and livestock and is environmentally friendly, and insect pests such as nilaparvata lugens, laodelphax striatellus, bemisia tabaci, aphids, bactrocera dorsalis, pomacea canaliculata and wigglers can be prevented and treated by the lemon insecticide.