The invention relates to the technical field of pyrometallurgy, in particular to a method for producing ferronickel through reduction smelting of a laterite-nickel ore flash furnace, which is short inflash reduction smelting time, high in speed, high in production efficiency, energy-saving and environment-friendly, and the reduction time is within one minute. Iron in the slag is reduced to prepare the iron-containing semi-steel alloy; remelting of said alloy is carried out to form qualified molten steel, meanwhile, submerged arc furnace slag is also obtained; the submerged arc furnace slag can serve as cement clinker to be conveyed to a cement plant to produce high-quality cement. The process is simple, the flow is short, qualified molten steel can be smelted and recycled, cement can be manufactured, economic benefits are good, environmental protection is facilitated, and hot materials subjected to multi-stage cyclone drying and pre-reduction directly enter a rotary kiln to be roasted; on one hand, the material buffering effect is achieved, and the material blocking problem caused when the hot materials directly enter the rotary kiln can be avoided; and on the other hand, throughfurther pre-reduction roasting of the rotary kiln, agglomeration of the materials can be achieved, and equipment and operation safety problems caused by direct feeding of the powdery materials into the furnace is avoided.