Functional plants, characterized by their ecological regulatory capabilities, are a group of plant species that attract the natural enemies of pest insects and pollinators, provide food sources and habitats for these, and repel pests. Since the discovery in 2012 that Cnidium monnieri is the predominant functional plant in North China, extensive research has been conducted to elucidate its mode and mechanism of action, and the effectiveness of growing it, culminating in the development of an innovative, ecological, regulation technology based on this species. This review synthesizes current research findings, systematically examines the fundamental biological characteristics, mode, and mechanism of action of C. monnieri, with particular emphasis on its performance as an ecological regulator in North China's predominant agricultural systems, including wheat, maize, peanut and cotton fields, as well as apple and pear orchards. Future research directions for C. monnieri are proposed, with the aim of promoting the use of this plant as one of the most important functional plants for ecological pest control.