The invention provides a level-200 polyesterimide enameled wire which is prepared from the following components in parts by mass: 37 to 53 parts of polyesterimide resin, 9 to 17 parts of composite fiber, 13 to 17 parts of a filler and 2 to 5 parts of an adjuvant, wherein the composite fiber is prepared from silicate fiber and carbon fiber according to a mass ratio of (5 to 8):1; the filler is prepared from silica aerogel and ceramic; the adjuvant is prepared from an acidic aqueous solution of tetraethoxysilane, fire retardant liquid and repair liquid. The invention further provides a method for preparing the level-200 polyesterimide enameled wire. Due to a creative component proportion and a creative process, the prepared enameled wire is excellent in mechanical strength, and is also excellent in high temperature resistance, insulating property and coolant resistance; once the surface is broken, the fire retardant liquid and the repair liquid can form a layer of anti-temperature insulating film, so that precious time can be reserved for repair of a line; moreover, the components are easy to obtain and low in cost, and the manufacturing process is relatively simple.