Politeness Principle is a seminal principle in pragmatic studies;research on politeness almost goes hand in hand with the blooming of pragmatics as an important branch in linguistics.Based their respective languages,both Chinese and western scholars,with Gu Yueguo,Leech and Levinson etc.as their representatives,have voiced their ideas in this field.It is the fact that politeness theory is closely linked with homogeneity and heterogeneity of languages that makes "politeness equivalence" an important criterion of "functional equivalence".This paper is designed to carry out a research on politeness equivalence in translation.The whole paper is divided into four parts:the first part is the introduction;in the second part,the author introduces typical politeness theories both home and abroad;the third part,with The Fortress Besieged as a frame of reference,is devoted to a survey of the application of politeness theory in translation;the last part is the summary of this paper.