The lexical collocation in English is an important content in the linguistics theory, and also a research topic which is more and more emphasized in English teaching practice of China. The collocation ability of English decides whether learners could masterly use real English in effective communication. In many years' English teaching practice, the author found that many college students often ignored the learning and study of the target language collocation, so they would make many collocation mistakes in English writing, dialog, and exams. The main representations and causes of these mistakes are analyzed in this article, and the main countermeasures of these mistakes would be proposed for teachers' teaching and students' learning.