The invention discloses a sudden water pollution accident warning and emergency disposal method and a sudden water pollution accident warning and emergency disposal system, and belongs to the field of water environment monitoring, warning and emergency disposal. According to the method, a typical pollutant is identified according to the type, concentration, main water quality parameters and other indexes of the pollutant, a sudden water pollution accident is classified, the sudden water pollution accident is verified by comparing the pollution indexes of the sudden water pollution accident with the pollution indexes of the most serious sudden water pollution accident of the corresponding type in history, the level of pollution of the sudden water pollution accident is determined according to the verification result, and an emergency disposal system of the corresponding level is started according to different levels of pollution to obtain a corresponding disposal scheme. As disposal resources and schemes of corresponding levels are adopted for sudden water pollution accidents of different levels, reasonable utilization of various emergency resources is ensured, and a disposal scheme can be obtained quickly. Moreover, inadequate response or excessive response after the occurrence of a sudden water pollution accident is avoided, effective warning for a drainage basin sudden water pollution accident is realized, and the damage caused by sudden water pollution incidents is reduced greatly.