The embodiment of the invention provides a rendering method for a power failure area. The rendering method comprises the following steps of: obtaining a transformer having power failure in a power grid topology, wherein the power grid topology is of a graphic topologic structure of a power device and comprises attribute data of the power device; obtaining meter box data having relationship with the transformer according to the attribute data of the transformer, and obtaining building data having the relationship with a meter box according to the meter box data; determining a building to be rendered in the power grid topology according to the attribute data of the transformer; and rendering the building according a preset power failure rendering rule. The embodiment of the invention further provides a rendering device for the power failure area. According to the embodiment of the invention, the problem of inexact rendering of the power failure area in the prior art is solved.