The invention discloses a method and a device for accessing power transformation data to a real-time or historical database. The method can include receiving the power transformation data of monitoring equipment of each manufacturer; converting the power transformation data to be in a uniform format; sending the power transformation data after conversion together with time stamps to the real-time or historical database for storing. The received power transformation data are converted to be in the uniform format meeting access requirements of the real-time or historical database, and the conversion strategy aims at the power transformation data of all formats, so that the problem that data access interfaces are large in number and varied due to the fact that each manufacturer arranges self-developed interface programs meeting own data format access requirements is solved, data interface development modes are simplified, development cost is lowered, and convenience is brought to uniform maintenance and management.