Abstract: Implicit negation is a special method of negation in English. When the affirmative form is used to express negative meaning, vocabulary, grammar, rhetoric and pragmatic expression which contain negative meaning are often adopted. The expression of implicit negation is implied and indirect. The politeness principle in pragmatics has been fully reflected in the implicit negation of English, especially the application of some standards such as appropriateness, praise and sympathy. In this way, the negative expression can also maintain a harmonious and friendly atmosphere.