The main effect of Si Jun Zi Tang is to strengthen the spleen and benefit the qi. It is a basic formula for treating spleen qi deficiency, which is relatively calm and simple in composition, with only four drugs, and is often used to treat symptoms such as weakness, tiredness of the limbs, loose stools and yellowish, lusterless complexion caused by spleen qi deficiency. Si Jun Zi Tang is not a large warm and hot formula, so clinical application will rarely cause fire due to too much tonic. Clinically, Si Jun Zi Tang is not recommended for patients with actual heat, such as wind-cold, wind-heat cold and cold-induced cough, asthma, fever and dry stools, nor for damp-heat evidence such as dizziness, headache, bitter mouth, dry throat and tinnitus caused by excessive liver fire.