The purpose of this study is to reveal the pattern of policy metaphor in the policy process of autonomous private high schools. To this end, the following research issues were set up: Who is using policy metaphor and how they are used? What is the policy belief in policy metaphor, and what is the relationship with policy advocacy coalition? What is policy metaphor highlighting, what is hidden, and what is the frame in it? Studies have shown that in the policy process of autonomous private high schools, policy actors have used stimulated and uncoordinated expressions. Administration, private school organizations, KFTA and conservative media used such as‘fish-shaped bun printing eduction’,‘killing an autonomous private high school’,‘autonomous private high school extermination policy’. Meanwhile, the New Progressive Party, KTU, the Parents Association for True Education and the progressive press used such as‘noble private school’,‘high school caste’and‘eduction old evils. These policy metaphor reflected the policy beliefs of‘marketism’and‘nationalism’, and shared among actors with the same policy beliefs and mediated the formation and maintenance of a policy advocacy coalition. And policy metaphors have activated certain frames, highlighting the advantages and hiding the disadvantages. Metaphor interfered with rational approaches to policy in the context of policy competition, used as an unreasonable mechanism, and caused extreme confrontation between pros and cons.