The invention relates to a method for detecting chemical combination residual chlorine in drinking water, and belongs to the technical field of drinking water chlorination disinfection. According to the method provided by the invention, a chemical combination residual chlorine instrument is used as a main body, during the detection, a probe is placed in the drinking water for monitoring, the result is converted into a micro signal, the micro signal is transmitted to a sensor, the micro signal is converted by the sensor into a micro signal, the micro signal is transmitted to an information processor, a data signal is formed after the signal is processed, the data signal is transmitted to an information memory and is compared with the data in the existing information memory to form a workingcurve of the relationship between the known current intensity and the unknown chemical combination residual chlorine concentration, and finally the chemical combination residual chlorine concentration in the drinking water is measured. The method provided by the invention has the effects that the detection is to separately detect free state residual chlorine and the chemical combination state residual chlorine, a single detection method of the chemical combination state residual chlorine is achieved, and the content of the chemical combination state residual chlorine in the water can be monitored quickly and accurately.