According to hospital size, nature and whereabouts of dealing with sewage, process selection. 1.4.1 Chinese medicine hospital classification is divided into infectious diseases hospitals and general hospitals. Hospital sewage treatment discharge where divided into discharged into natural water bodies and municipal sewage discharged into the urban sewage treatment plant in two categories. 
 Hospital sewage treatment by the process must ensure that the effluent standard, mainly used in three processes: to strengthen the treatment effect of a treatment, secondary treatment, and simple biochemical treatment. 
 Process selection principles are: 
 1.1 The Hospital for Infectious Diseases secondary treatment, and the need for pre-disinfection. 
 1.2 and the treated effluent discharged into the natural water body and above county hospital must be a secondary treatment. 
 1.3 and the treated effluent discharged into city sewers (downstream has two sewage treatment plants), the hospital recommended secondary treatment, the treatment effect using a process must be strengthened. 
 1.4 for the small general hospital in economically underdeveloped regions, the conditions are not met, can be simple biochemical treatment of the progressive realization of secondary treatment as a transition processing measures, or to strengthen the treatment effect of primary treatment.