The invention discloses a three-dimensional safety monitoring method for an operation inspection space of a transformer substation. Laser scanning technology is utilized for quickly and accurately acquiring three-dimensional space data of the transformer substation. A three-dimensional simulation model of the transformer substation is established according to the three-dimensional space data. A safe area is set in the three-dimensional simulation model. Real-time tracking and real-time monitoring are performed on personnel and equipment in field, thereby ensuring safe distance between the personnel/equipment and live equipment. Furthermore the three-dimensional safety monitoring method is different from a traditional safety monitoring mode in working field and realizes intelligent space monitoring. The three-dimensional safety monitoring method has advantages of effectively improving personnel safety of field operation personnel, ensuring high use safety of electric power equipment and construction equipment, improving stability and reliability in operation of the transformer substation, and reducing unnecessary safety accidents and property loss. Therefore the three-dimensional safety monitoring method has relatively high economic benefit and high application value.