Abstract: In this paper, the monitoring method of total residual chlorine in medical wastewater was optimized. Under the condition that the titration end point of the calibration experiment was difficult to observe, the calibration experiment of the same substance in the chemical oxygen demand measurement was introduced to verify each other,which effectively improved the accuracy of the concentration calibration of the titrator. Through the analysis and determination of the standard sample, the experimental results showed that the determination results of this method were in the range of standard sample concentration, and the precision and accuracy met the requirements of quality control. This method would provide another effective way to accurately obtain the monitoring data. In addition, the problems existing in the delivery of chlorine-containing disinfectants in the wastewater of medical institutions were analyzed and summarized, and corresponding rectification suggestions were put forward to ensure that the residual chlorine concentration in the medical wastewater met the relevant standards.