The purpose of this paper is to introduce professor Huang Huang’s experience in differential diagnosis and treatment of gastrointestinal diseases with classical formulas. Most of the prescriptions prescribed by professor Huang can be elucidated by the contents of classics. He pays attention to the indications of each prescription, emphasizes the adjustment of patients’ physique and emotion, focuses on the addition and subtraction of prescriptions and the use of combined prescriptions, and pays attention to the time and methods of taking medicine. And one proven case is presented.