Zhang Zhongjing advocates "assiduously seeking ancient teachings" and earnestly studies and summarizes the theoretical experience of predecessors.

He has carefully studied the ancient medical books such as Su Wen, Ling Shu, Nan Jing, Da Lun of Yin and Yang, and Yao Lu of Pregnancy. Among them, Su Wen had the greatest influence on him. "Su Wen" said: "People with husband fever are all typhoid fever and the like." He also said that "when people are injured by cold, they are sick and hot." Zhang Zhongjing developed this theory according to his own practice. He believes that typhoid fever is the general name of all fevers, that is, all diseases caused by exogenous diseases can be called "typhoid fever". He also carefully studied the treatment principle of "syndrome differentiation and treatment" left by predecessors, thus putting forward a new view of "six meridians on typhoid fever"

in addition to "assiduously seeking ancient teachings", he also "learned from many prescriptions" and extensively collected effective prescriptions for ancient and modern treatments, even folk prescriptions. He studied many kinds of specific treatments that people like to use, such as acupuncture, moxibustion, warm ironing, rubbing medicine, sitting medicine, bathing, moistening and guiding, soaking feet, ear irrigation, ear blowing, sublingual medicine, artificial respiration and so on, and accumulated a lot of information.