The invention provides a method for coarse grain separation and dry-type powdering of granite pegmatite. The preparation method comprises the steps that (1) crude ores of granite pegmatite are crushedand graded, so mineral particles 1 with a particle size of 3mm-20mm and mineral particles 2 with a particle size of -3mm are obtained, the mineral particles 1 are processed with photoelectric sorting, and quartz particle concentrate ores and feldspar particle concentrate ores are obtained; (2) the mineral particles 2 and the feldspar particle concentrate ores are processed by a high-pressure rollgrinding-air classification closed-cycle powdering system, so fine grain materials and a gas material mixture are obtained, feldspar powder 1 is obtained after magnetic sorting and purification of the fine grain materials, the gas material mixture is processed by a powder collector for gas-material separation, and feldspar powder 2 is obtained; and (3) the quartz particle concentrate ores are treated by hammer crushing, screening, magnetic sorting and purification, and a quartz product is obtained finally through screening and grading. The method provided by the invention has the beneficial effects of short processes, the small quantity of devices, a large processing amount, a small particle size of the product and the like; energy consumption cost is reduced; and the method can be applied to industrial and large-scape production.