Peroxone is an advanced oxidation process for the removal of antibiotics in hospital wastewater. In this study, ORP monitor was combined into the system to obtain the optimum ratio of H2O2 to O3 by automatically adjusting the dosage of H2O2 and O3. Relationships between ORP, pH, and H2O2 and O3 concentrations were observed during the process. The effectiveness of the peroxone process for antibiotics removal was investigated by using ofloxacin as a model substance. An ORP between 200 mV and 900 mV is used for H2O2/O3 control. The correlation between ORP and the O3/H2O2 shows potential for use as a parameter to control the peroxone process. The working optimal range of ORP was determined to control the most effective removal of ofloxacin. The experiment results show ORP between 250 mV and 300 mV or 800 mV and 900 mV is suitable for H2O2/O3 control. The study investigated the feasibility of using ORP as a parameter to control antibiotic removal in hospital wastewater by the peroxone process.