The invention provides a method and device for determining a time section of a power system and electronic equipment, in the technical field of power systems, and can solve the technical problem thatthe accuracy of a similarity result of the time section is low. The method comprises the steps of obtaining a historical time section of a power system; taking the target time section and the time section with the minimum similarity with the target time section in the historical time sections as initial clustering centers respectively, and clustering the historical time sections to obtain a firstcluster corresponding to the first time section and a second cluster corresponding to the second time section; repeating the execution steps: re-determining the center of the second cluster as a thirdtime section, taking the first time section and the third time section as new clustering centers, and clustering the historical time sections to obtain a first cluster corresponding to the first timesection; and screening the plurality of time sections in the first cluster to obtain a section with the highest similarity with the target time section.