The invention relates to a process for roasting waste sand into a precoated sand material. The process comprises the steps of shakeout, magnetic separation, crushing, screening, magnetic separation, roasting, dedusting, cooling and storage. When crushed and magnetically separated sand is roasted, the sand is required to be fed into a preheater for preheating, and then is fed into a roasting furnace for roasting. A passage for bearing the sand is stepped when the sand is in the preheater, the sand in the stepped passage is in a flocculated flow state, and when the sand is roasted, natural gas is jetted from three direction-adjustable jet tips in the roasting furnace to process the sand. Before being roasted, the sand is required to be preheated, so that the high-temperature heat exchange time of the sand in the roasting furnace is short, and the roasting efficiency and the roasting quality are improved. The sand is roasted at high temperature by the natural gas, so that the generation of an inert gas during the roasting is avoided. In addition, the three adjustable natural gas jet tips are adopted, so that the sand can be uniformly heated when roasted.