In the field of neurolinguistics, mechanisms of code-switching have been given extensive attention. As translation is characterized as one type of code-switching, the translator’s cognitive mechanisms can be discussed in neurolinguistic terms. From this interdisciplinary perspective, the paper bases its analysis of mistranslation on the student translators’ cognitive deficits detected in their syntactic and semantic processing, lexical or proposition exacting. It also finds that there are deficits in the novices’ code-switching from the source language text to the target one, which bears such a strong similarity to the clinical symptoms of aphasic patients. The finding shows that neurolinguistics and aphasia studies indeed provide a cross-disciplinary perspective for further study on the translator’s mistranslation.