This paper briefly introduced the evolution of purification technology for drinking water over time. After description of the 1st generation processes in the beginning of the 20th century—conventional processes and the 2nd generation processes in 1970s—advanced treatment processes, a tertiary processes—UF (ultrafiltration) based on integrated processes was proposed. Moreover, reaction measures (dosing variety of regents for different contaminants) for urban source water emergencies were illustrated in brief. A new technology of KMnO4 and potassium permanganate composite (PPC) for drinking water purification which was developed by Harbin Institute of Technology (HIT) was concisely introduced.