The magneto-optical properties of a Al/BiGaDyIG double layer fine grain thinfilm crystalized with a rapid recurrent thermal annealing method has been investigated. Theeffective Faraday angle of the double layer film is over about 0. 25 degree than that of thecommon single layer film, and its Faraday angle inereases with the number of the rapidrecurrent annealing increased, which is due to the fineness of the grains and the interfaceinterference between the Al film and the garnet film. Meanwhile, the Al+3 ions diffuse into garnet film and substitute the Fe3+ ions in octahedral and tetrahedral sites, it results in a decrease of Curie temperature (140～161 ℃). These results are very promising for increasing the recording density and signal-noise-ratio.