The invention relates to the technical field of botanical pesticides, and discloses a botanical pesticide for urban greening projects and a preparation method of the botanical pesticide. The botanical pesticide comprises effective components, mainly prepared from a croton tiglium extract, a rhizoma arisaematis extract, a ginger extract, a hibiscus extract, a geranium extract, a marigold extract, an artemisia capillaries extract, a surfactant, an anti-freezing agent and deionized water, and in addition, the botanical pesticide is mainly prepared by steps of washing, filtering, concentration and the like. On one hand, the botanical pesticide is capable of effectively inhibiting damage of common injurious insects in urban gardens, has a good prevention effect on common pests such as aphids, red spiders, leaf rollers and fall webworms of urban greening plants, and furthermore has an effect of greening and beautifying cities; on the other hand, the administration times of chemical pesticides can be reduced, the lasting period can be prolonged, the environment burden can be alleviated, and a good leisure and entertainment atmosphere can be provided for urban citizens. Meanwhile, the preparation method disclosed by the invention is simple and feasible, low in cost and applicable to greening projects.