This paper summarized Professor FANG Dingya′s experience in staged treatment of Behcet′s syndrome uveitis based on the theory of collateral disease. It is believed that the heat toxin entering the collaterals and the toxin stasis deep in the collaterals are the root causes of repeated occurrences of Behcet′s syndrome uveitis. Following the basic principle of "collaterals performing its functions when there is free flow" and considering the pathological characteristics

it can be divided into active stage

protracted stage and late stage for syndrome differentiation and treatment. At the active stage

it is suggested to clear heat and resolve toxins

drain dampness

and unblock the collaterals

and modified Gancao Jiedu Decoction（甘草解毒汤） is appropriate; at the protracted stage

it is advised to eliminate residual pathogen

clear heat and unblock the collaterals with modified Simiao Yongan Decoction（四妙勇安汤）; at the late stage

it is appropriate to use modified Danggui Yinzi（当归饮子） to warm the channels and nourish the blood

care the vessels and unblock the collaterals.