The invention discloses a botanical high-efficiency insecticide for plants and flowers, and a preparation method thereof. The pesticide is prepared from, by weight, 16-25 parts of wilfordine, 8-14 parts of root of Phytolacca acinosa Roxb, 6-11 parts of Rhamnus utilis, 7-11 parts of Baeckea frutescens L., 3-5 parts of Fructus Viticis, 4-7 parts of Crofton Weed, 2-6 parts of Eclipta prostrata, 15-21parts of matrine, 7-12 parts of tung oil tree seed oil and 6-12 parts of Radix Clematidis. The wilfordine, root of Phytolacca acinosa Roxb, Rhamnus utilis, Baeckea frutescens L., Fructus Viticis, Crofton Weed, Eclipta prostrata, matrine, tung oil tree seed oil and Radix Clematidis are effectively proportioned to prepare the insecticide, so the collection cost of the raw materials is low, and theinsecticide is simple and convenient to prepare, has very good insecticidal effects on rice, vegetables, fruit trees and tea trees, has no pollution to the environment, and meets green production requirements; and the insecticide also has the advantages of satisfactory protection of seedlings, effective killing of pests, small toxicity, and no influences on nursery stocks or human bodies.