The preparation method for the compound, composition and application thereof in preparing an angiotensin II receptor antagonist or application in preparing medicine for preventing and/or treating hypertension, chronic heart failure and diabetic nephropathy. After entering a human body, when releasing azilsartan, the compound releases hydroxyligustrazine or NO at the same time, thus generating a synergistic effect with azilsartan. The compound therefore has stronger and longer blood pressure lowering effect, more obvious and longer lasting heart rate lowering effect and high safety, and achieves ideal protective effect for heart and kidney functions.