This paper summarized professor ZHAI Shuangqing's clinical experience in treating obsessive-compulsive disorder （OCD） from the perspective of "

qi

constraint with harassing phlegm". It is believed that

qi

constraint with harassing phlegm is the core pathogenesis of OCD.

Qi

constraint and harassing phlegm interact with each other and together contribute to the disease. The formation of "

qi

constraint with harassing phlegm" is closely related to dysfunction of

zang

-

fu

（脏腑） organs such as the heart， spleen， liver， and gallbladder. Clinical treatment should focus on rectifying

qi

and dispelling phlegm， calmi

ng the mind with heavy sedatives. Based on the self-designed

Jieyu Huatan Decoction

（解郁化痰汤）， treatment should be tailored to the patient's condition and stage of the disease， with prescriptions incorporating medicinals that fortify the spleen and boost the stomach， nourish the heart and calm the mind， soothe the liver and promote gallbladder function， and nourish

yin

and warm

yang

. At the same time， it is emphasized to flexibly select heavy sedatives such as Longgu （

Os Draconis

）， Longchi （

Dens Draconis

）， Muli （

Concha Ostreae

） and Zhenzhumu （

Concha Margaritiferae Usta

） to calm the mind.