Pronounced as the English letters — 'ay-eye' (or in pinyin terms, ài-ài). Modern Mandarin freely embeds English letter-acronyms in speech (CEO, KPI, OK, AI, MBTI). The full Chinese name
人工智能 (réngōng zhìnéng, 'artificial intelligence') exists and appears in formal/written contexts, but conversational speech overwhelmingly says AI.