Distributed wastewater treatment network (DWTN) has significant advantages over centralised one. This paper mainly reviews the methods proposed by our group for the design of DWTNs. Pinch analysis and mathematical programming methods are briefly discussed as well. By analysing the features of DWTNs, our group pointed out that it is very important to minimize unnecessary stream mixing to reduce the total treatment flowrate of a DWTN. Based on this insight, we proposed a series of design methods for both single and multiple contaminant systems. The constraints on the maximum inlet concentrations of treatment processes were considered as well. The methods of our group can handle complex problems with simple calculation and have clear engineering meaning.