This paper argues that metaphorical thinking, as well as metonymic thinking, occurs in the mental process of translation, and that the philosophical principle of identity provides a new perspective for the study of metaphor. Given that, the process of translation is one producing metaphors in that they are isomorphic. Therefore, the process of translation can be viewed as one in which the tenor of the target language units replaces the vehicle of the source language units. Following that, this paper analyzes the translation process of metaphorical languages, concluding that when the psycho-physical isomorphism can be established directly, the method of literary translation is chosen, while when the psycho-morphism is established in an indirect way, the method of literal translation or of literal translation plus translators’ notes might be employed.