The invention discloses a high-grade potassium chloride production system and a method thereof. The system comprises a raw ore screening and concentrating system, a size mixing system, a floatation system, a low sodium concentration and dehalogenation system, a cold crystallization and thick potassium screening system, a thick potassium concentration and dehalogenation system, a refined potassium washing and dehalogenation system, a piling and filtering storage stock ground system, a breaking and conveying system and a drying cooling, packing, stacking and line crossing conveying system, and all the systems are sequentially connected and are arranged in a three-dimensional mode. Materials enter a next system in a self-flowing mode. An automatic dosing, automatic water adding and dehalogenation device is adopted, a spiral screen type centrifugal machine is used for replacing a horizontal belt type filter, and other technology improvements are adopted, so that the potassium chloride grade is improved to 98 percent from 95 percent, the piling and filtering technology is adopted in the system so that the natural gas using amount can be saved, production operation is convenient, and equipment operation is stable.