Abstract: The paper, based on the theory of grammatical metaphor and tense system in Systemic Functional Grammar (SFG), explores a particular aspect of academic discourse:the English tense of projecting verbs, which is an essential feature of academic discourse.However, the function of the tense of projecting verbs has not been fully explored and explained.By applying the principles of grammatical metaphor in SFG to the analysis of the tense of projecting verbs in the English academic discourse, we find that grammatical metaphor can help to provide further explanations as to what types of projecting verb tenses are used to achieve certain effect in academic discourse.Finally, from the discussion and the analysis, this research concludes that grammatical metaphor plays an important role in constructing the deeper, complicated metaphorical meanings and functions of the tense of projecting verbs in academic discourse.