Aiming at the prominent problems such as the aging and disrepair of drainage networks, the widespread mixed connection of rainwater and sewage, and the low efficiency of inspection in old residential areas, a precise inspection scheme integrating multiple technical means is proposed. By systematically sorting out the typical disease characteristics of drainage systems in old residential areas, and analyzing the limitations of traditional inspection methods and single water quality and quantity analysis technologies, a three-stage technical framework of “basic investigation - key screening - precise detection” is constructed. This framework integrates the technologies such as pipeline network attribute census, rapid water quality monitoring, dynamic flow tracking and CCTV/QV pipeline detection to realize the accurate identification and priority ranking of problematic pipeline sections. Practice shows that this technical system can significantly reduce the scope of invalid detection, lower the inspection cost by more than 30%, and provide the reliable technical support for the quality and efficiency improvement, and reconstruction of drainage pipe networks in old residential areas.