Abstract: In order to meet the requirements for water reuse after treatment of domestic sewage from the hospitals, the process of “pretreatment+bio-contact oxidation+high efficiency precipitation+filtration disinfection” was proposed according to the characteristics of domestic sewage from hospitals, and the optimal process conditions determined by a small trial test. The process was applied in the upgrading and transformation project of domestic sewage in a specialized hospital in Tianjin. The optimal process conditions were determined by the small trial test, i.e. volumetric load of 0.50 kg∕(m ³·d), pH of 7.5-8.0, gas-water ratio of 15, the joint dosing of poly aluminum chloride and polyacrylamide (15.0,1.0 mg∕L respectively) and ClO₂ dosing of 12 mg∕L. The engineering application results showed that the process was in good condition and the water quality of effluent reached the reuse water quality requirements for toilet flushing of Standard for Municipal Sewage Reuse, Municipal Mixed Water Quality (GB∕T 18920-2002).