Vocabulary acquisition study is the theory of how to enlarge vocabulary. In some countries, especially using English as second language, learners should learn words not only according to the sound, form, meaning, and other characteristics, but also selecting the appropriate teaching methods to strengthen the vocabulary learning interest and efficiency. In this paper, the appropriate teaching methods just refers to use prefixes and suffixes to illustrate words is an effective way and phrase via related prepositions, which provide learners with an effective way to enlarge their vocabulary. With the help of the methods, learners’ learning interest can be excited; to some extent, their English level be improved. Vocabulary acquisition study is the theory of how to enlarge vocabulary. In some countries, especially using English as second language, learners should learn not not according according to the sound, form, meaning, and other characteristics, but also selecting the appropriate teaching methods to strengthen the vocabulary learning interest and efficiency. In this paper, the appropriate teaching methods just refers to use prefixes and suffixes to relate words help of the methods, learners’ learning interest can be excited; to some extent, their English level be improved.