Cognitive theory, based on conceptual metaphor, discusses the cognitive analysis of the time distance under the were-conditional subjunctive mood. It further gives a cognitive analysis from the perspectives of real distance, emotional distamce and interpersonnal distance and further analysis is presented from the sentence emotion, sentence meaning and knowledge reconstruction. This type of subjunctive mood represents the achievements in the field of cognition by human being and lays a solid theoretical significance for a better understanding of this grammatical phoenomenon