Existing　researches　on　ontology　in　the　power　quality　domain　have　such　disadvantages　as　lack　of　standardized　construction　method,　unclear　relationships　between　terms　and　poor　practicability,　as　well　as　the　inability　to　automatically　update　with　the　domain　development.　Aiming　at　the　above　problems,　an　ontology　construction　method　based　on　power　quality　standard　files　is　proposed.　Firstly,　the　sentence　structure　and　semantic　relationship　in　the　power　quality　standard　files　are　analyzed　to　form　a　relationship　function　to　realize　the　semantic　association　between　terms.　Secondly,　the　text　is　processed　and　domain　terms　are　extracted　by　building　a　professional　vocabulary　of　power　quality　and　adopting　natural　language　processing　technology.　Then,　according　to　the　domain　terms　and　their　functional　relationships,　the　specific　terms　are　mapped　to　different　instances　in　the　ontology　unit　framework　to　construct　an　ontology　unit　in　the　power　quality　domain　in　four　dimensions　of　stage,　phenomenon,　object　and　technical　supervision.　Finally,　based　on　the　technical　requirements　of　power　quality　at　different　stages,　an　ontology　model　with　close　multi-dimensional　knowledge　connections　is　formed.　The　construction　method　can　use　standard　files　to　build　ontology　models　of　different　analysis　objects　at　various　stages,　and　support　data　sharing　between　systems　and　human-computer　interaction　in　Chinese.　The　modeling　process　is　simple　and　easy　to　standardize.　And　the　ontology　can　be　updated　with　the　revision　of　standard　files,　so　it　has　good　practicality.　©　2020　Automation　of　Electric　Power　Systems　Press.