Terpenoids are present in all organisms but are especially abundant in plants, with more than 30,000 compounds. Not only do they play an important role in the life of plant, but also have high commercial values. However, the content of many important terpenoids in plant is very low. Therefore, how to improve the inefficient production of terpenoids is an urgent task. Metabolic engineering has been one of the most potential technologies to improve terpenoids production in recent years, following the study of metabolic pathway and regulation mechanism of terpenoids. Although there are some breakthroughs, metabolic engineering of terpenoids is still full of challenges because of the lack of knowledge on metabolic control of most terpenoids. Functional genomics approaches, including transcriptomics, proteomics and metabolomics, are potential tools for exploring of metabolic engineering. Integrating transcriptomics and metabolomics is an effective way to discover new genes involved in metabolic pathway. In this paper, the representative research outcomes about the metabolic engineering of terpenoids in plant were reviewed concisely and then the application of functional genomics approaches to study metabolic pathway and regulation mechanism of terpenoids and the strategies for metabolic engineering of terpenoids were discussed.