Abstract： Since the theory of expelling fire constraint was put forward in the Huangdi Neijing， Chinese medicine practitioners of all dynasties have continued to elucidate this theory. “Fire constraint” emphasizes on “constraint” and it is bound to “expel” the “constraint”. The key to “expelling” is to make the best use of the circumstances to give way to pathogenic factors to go out. In terms of the pathogenesis of method of “expelling fire constraint”，it is to treat qi- blood imbalance from the heart and liver to soothe qi movement. That is to say，the treatment of fire constraint should make the best use of the circumstances and diffuse and soothe qi movement to let fire constraint externally expelled. The key to syndrome differentiation of Shengjiang power is disorder of qi movement；no matter patients are with cold，heat，deficiency or excess syndrome，as long as their qi movement is counterflow，they can be treated with modified Shengjiang power to regulate the qi movement of all zang-fu organs，so as to achieve the harmony of qi，blood，yin and yang. Insomnia is caused by stagnation of qi. Therefore，it is of great clinical significance to treat insomnia from the theory of expelling fire constraint.