Coercion is a widespread linguistic phenomenon,which is the supernormal collocation between linguistic components.Coer-cion,as a cognitive process,is an effective explanation of the supernormal collocations by repairing or tuning the semantic conflicts be-tween the components within the phrase structure with the help of the corresponding grammatical means in a certain context.Therefore,the realization of coercion requires driving factors and operating mechanism,and it is the result of the mapping on grammatical structures.On the basis of previous studies,this paper explains the principle of coercion in detail and proposes the deletion principle to further im-prove the theoretical analysis of this linguistic phenomenon.