The invention provides a ferro-nickel slag ceramic and a preparation method thereof. The preparation method comprises the following steps of selecting one or multiple of quartz, silicon and aluminum-rich raw material and calcium raw material; mixing 20 to 65wt% of ferro-nickel slag, 0 to 10wt% of quartz, 20 to 70wt% of silicon and aluminum-rich raw material and 0 to 30wt% of calcium raw material;grinding, granulating, forming, and firing, so as to obtain the ferro-nickel slag ceramic. The preparation method has the advantages that the ferro-nickel slag can be used in a batch way, the preparation method is simple, the implementing is easy, and the industrialized production is favorably realized; the crystal phases in the prepared building ceramic materials (ceramic tiles and ceramic sintering bricks), industrial ceramics and other ceramic materials contain one or multiple of anorthite, spinel, olivine and cordierite, the sintering is easy, and the mechanical property is excellent.