PURPOSE: A manufacturing method and apparatus for casting sand are provided to recycle sand type slag which is generated by refining and concentrating nickel ore, as casting sand, thereby releasing the scarcity of resources of silica. CONSTITUTION: A manufacturing method of casting sand comprises a step of obtaining sand type slag by heat-treating nickel ore passed through a pulverizer, a filter, etc, pulverizing the same in a pulverizer, and sorting nickel in a gravity-ore separator and a magnetic ore separator; a step drying the sand type slag in a rotary drier(2) at 150-160 °C from the moisture content near 8% to the moisture content of 0.02%; a step of cooling the sand type slag to room temperature by a rotary cooler(3); a step of spheroidizing the same in a rotary MMR(5); a step of manufacturing a first product by sorting the sand type slag per particle sizes in a round screen(6); a step of crushing large residue sand type slag which is not productized in mill(7); and a step of manufacturing a second product by sorting the crushed sand type slag per particle sizes in the round screen.