[LI, Xiaosong 李小松, WANG, Xingfu 王兴富, XIE, Kangmin 谢康民, WANG, Shijun 王石军, HUANG, Long 黄龙, YU, Qiuping 俞秋平, ZHAO, Yuanhai 赵元海, ZHANG, Zhenjie 张振杰, TIAN, Hongbin 田红斌, ZHANG, Shengtai 张生太, REN, Hongwei 任红伟, YU, Jianguo 于建国, SONG, Xingfu 宋兴福, HAI, Jizhong 海吉忠, YU, Xuefeng 于雪峰, SHI, Zhonglu 史忠录, QU, Xiaorong 屈小荣, LI, Jianye 李建业, REN, Qingfeng 任青峰, HAO, Hongjun 郝红军, JIANG, Zhonghua 蒋中华, MENG, Hao 孟浩] 28 Golmud Huanghe Road 中国青海省海西蒙古族藏族自治州格尔木市黄河路28号, Qinghai 816000Haixi Mongolian and Tibetan Autonomous Prefecture Qinghai 816000 Provided are a method and system for producing potassium chloride that are capable of recycling a byproduct. The system comprises: a raw ore processing system (1), a pulp mixing system (2), a flotation system (3), a low-sodium concentration and dehalogenation system (4), a cold crystallization and crude potassium screening system (5), a crude potassium concentration and dehalogenation system (6), a refined potassium washing and dehalogenation system (7) and an overflow liquid and filtrate processing system (8). The method comprises: a carnallite ore pulp is sequentially processed through the above systems to obtain an overflow liquid, a filtrate, a tail salt and a potassium chloride product, etc. in each stage. The system and method increase the yield of potassium chloride and save on costs. Provided are a method and system for producing potassium chloride that are capable of recycling a byproduct. The system comprises: a raw ore processing system (1), a pulp mixing system (2), a flotation system (3), a low-sodium concentration and dehalogenation system (4), a cold crystallization and crude potassium screening system (5), a crude potassium concentration and dehalogenation system (6), a refined potassium washing and dehalogenation system (7) and an overflow liquid and filtrate processing system (8). The method comprises: a carnallite ore pulp is sequentially processed through the above systems to obtain an overflow liquid, a filtrate, a tail salt and a potassium chloride product, etc. in each stage. The system and method increase the yield of potassium chloride and save on costs.