The invention belongs to the technical field of petrochemical industry and discloses a method for performing substance division and classification on different components of a high-emulsification oil-water mixing system. The method is implemented by a conductivity measuring instrument arranged on an outer transportation pipeline of a settling tank, the conductivity measuring instrument measures the conductivity according to the set internal measuring time and transmits the measured conductivity data to a data processing and logical control system, the data processing and logical control system receives the conductivity data, control on opening or closing of a liquid inlet valve of each collecting and processing system is realized through deviation size obtained by comparing a calculation value or measuring value and a threshold value in a corresponding group phase, so that the aim of separating different group phases in the settling tank is fulfilled. By the method, whether the liquid inlet index (water content of oil phase or oil content of water phase) accords with the feeding index requirement of the corresponding process treatment unit can be judged quickly; in addition, an oil layer, a high-emulsification oil-water mixing transition layer and a water layer can be distinguished, and support is provided for subsequent targeted treatment.