The invention relates to an artificial fish reef, in particular to a direct separation type artificial fish reef which comprises column-shaped falling blocks and a plurality of first plastic bottles. Bottle mouths of the first plastic bottles are provided with threads. Bottoms of the first plastic bottles are removed. The first plastic bottles are in threaded connection with the falling blocks through the threads on the bottle mouths. An inner cavity of each plastic bottle forms a cave, and the open bottom end of each plastic bottle forms a cave opening. The direct separation type artificial fish reef can be conveniently made of abandoned articles, is convenient to recover and good in protection performance, and solves the problems that an existing fish reef consumes effective resources in construction, free of effective caves, incapable of forming caves dense in number, and inconvenient to recover.