Vocabulary teaching is of great significance in senior high school English teaching, but the current senior high school English vocabulary teaching deviates from the thematic context and tends to mechanical memory, leading to inefficient vocabulary learning for students. This paper takes Unit 2 Food for thought in the second volume of English textbooks published by FLTRP edition as an example to conduct teaching practice research. It elaborates on relevant design ideas and proposes teaching strategies from three aspects: discovering themes, focusing on themes, and deepening themes.