Sludge Management has become an esstntial environmental issue in modern society. This paper overviewed the current status of sludge management research and development. We briefly reviewed the typical characteristics of sludge and its constiuent flocs. Afterward, several important processes in sludge treatment, including conditioning, dewatering, disinfection, hydrolysis, thermal treatment, and resource utilization were addressed. The updated progress in floc structure study was highlighted.