set yourself up as something
phrasal verb with set verb uk/set/ us/set/ setting | set
UK often disapproving
自称是，自命为
to say that you are a particular type of person
He sets himself up as an expert on vegetable growing, but he doesn't seem to me to know much about it. 他以蔬菜种植专家自居，但在我看来他对此懂得并不多。