五体投地 is a four-character idiom (成语) that literally describes the Buddhist practice of prostrating oneself with all five limbs (head, two hands, two knees) touching the ground. Figuratively, it expresses the highest level of admiration or awe for someone's skill, talent, or achievement — equivalent to 'I'm not worthy' or 'I bow to you' in English. You can use it as a predicate or complement after 佩服 or 崇拜.