Abstract: In recent years, relevance translation theory has been widely applied in the study of translation theory. The paper aims to explore the relationship between the English majors'subjectivity as translators and their mistranslation based on the integration of relevance translation theory with two stages of translation, namely, comprehension and expression. During the stage of comprehension, ineffective application of the translator's subjectivity results in the failure of the acquisition of the optimal relevance and leads to unintentional mistranslation. On the stage of expression, the indiscreet attitude of English majors towards the target language may directly result in the unconscious unintentional mistranslation; while their bilingual incompetence may cause a forced concession, which is conscious unintentional mistranslation. An effective application of the translator-s subjectivity enables a good reflection of the optimal relevance in the target language.