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Industrial production of lithium hexafluorophosphate enterprises,mostly used a process associated with hydrogen fluoride [1] which not only had highly toxic but also had particularly high corrosion resistance requirements to the equipment.The residual hydrogen fluoride poses a potential threat to the safety of the battery.The paper studied the solubility of KPF6/LiCl/LiPF6/KCl in acetonitrile aiming at providing a process for manufacturing LiPF6 in a moderate way.The solubility of KPF6/LiCl/LiPF6/KCl in acetonitrile was measured using classic isothermal dissolution method [2].The results show that with an increase of the temperature,KPF6’s solubility in acetonitrile decreases,LiPF6’ solubility in acetonitrile increases,but the solubility of LiCl in acetonitrile is slightly varies with increasing temperature; KCl’s solubility in acetonitrile is very small,it can be seen as the insoluble material.Ideal model [3],apelbat equation [4] and polynomial empirical equation [5] were applied to model the solubility of the four substances in acetonitrile,and according to the principle of minimum error,polynomial empirical equation was the appropriate way to describe the solubility law of the four substances in acetonitrile.The formulas were as follows: KPF6: x1=1.17759×10-7t3-1.03004×10-4t2+0.02961t-2.74273; LiPF6: x1=2.39167×10-8t3-1.12458×10-6t2-0.00359t+0.60544; LiCl: x1=6.75926×10-9t3--5.65249×10-6t2+0.00157t-0.1437.According to the solubility characteristics of the four substances in acetonitrile,a noval production method of lithium hexafluorophosphate is put forward which potassium hexafluorophosphate is reacted with lithium chloride,at a room reaction temperature and atmospheric pressure.After the separation of the potassium chloride,by cooling,crystallization,recrystallization,drying of the solution,the high purity lithium hexafluorophosphate can be obtained.