This paper considers cognitive linguistics as the guide to explore the feasibility of vocabulary teaching based on conceptual metaphor. Following the classification of conceptual metaphor, the paper probes into concrete effects of vocabulary teaching under the guidance of ontological metaphor, structural metaphor and orientational metaphor. Through detailed analysis, conceptual metaphor illuminates polysemy teaching, lexical collocation teaching and idiom teaching. Hence, it contributes to tackling the existed problems in the course of vocabulary teaching and cultivating students’ competence of cognitive acquisition.