Input Hypothesis” is the core of Krashen‟s language
acquisition theory, which is proved to be of substantial influence among second language educators in China. But we can find the impracticability and one-sidedness of “Input Hypothesis”. In 1980s Swain put forward “Output Hypothesis”, maintaining that output plays an equal important role in
the process of SLA. Analyzing “Input Hypothesis” and “Output Hypothesis”, the paper puts forward combination of these two hypotheses in English teaching at vocational college, so as to
advance students‟ English acquisition, which is proved by experimental teaching.