The invention relates to a method for producing microcrystalline glass by use of ferro-nickel hot molten slag, which comprises the steps of smelting ferro-nickel hot molten slag from laterite intermittently discharged from a slag tap, and feeding into a hardening and tempering electric furnace or tank furnace; adding a hardening and tempering agent, controlling the temperature of the hardening and tempering furnace, stirring with nitrogen, melting the hardening and tempering agent, sufficiently and uniformly mixing the hardening and tempering agent and the hot molten slag, and intermittently discharging the melt; putting the melt into a thermal insulation electric furnace or tank furnace through a chute, preserving heat and continuously discharging the melt; performing continuous calendering, nucleating, crystallization and annealing by the existing overall crystallization process to obtain the diopside-based CaO-MgO-Al2O3-SiO2 system microcrystalline glass. By adopting the smelting ferro-nickel hot molten slag as a raw material to produce microcrystalline glass, the energy consumption is reduced, and the raw material cost is saved. The method is favorable for environmental management, turns waste into wealth to realize secondary comprehensive utilization of resources, and reduces environmental pollution and influence on the environment caused by smelting slag stockpiling.