The present disclosure relates to the technical field of Lithium Ion Batteries, and in particular to a low-temperature Lithium Ion Battery electrolyte and a preparation method thereof, and a Lithium Ion Battery. The low-temperature Lithium Ion Battery electrolyte includes an electrolyte salt and an organic solvent; and the organic solvent includes fluorocarboxylate ester, fluorocarbonate ester, and 1,3-dioxolane. The fluorocarboxylate ester has a low freezing point, and is suitable for being used as a low-temperature electrolyte solvent; the fluorocarbonate ester is used as a co-flux, and is mixed with the fluorocarboxylate ester to adjust low-temperature performance and film-forming property of the electrolyte; and battery impedance is significantly reduced after the 1,3-dioxolane with a low freezing point and viscosity is introduced. The low-temperature Lithium Ion Battery electrolyte of the present disclosure may effectively improve the conductivity of lithium ions at low temperatures, which is conducive to the performance of the capacity of the Lithium Ion Battery at low temperatures, in particular, the discharge specific capacity and capacity retention of the lithium iron phosphate Lithium Ion Battery at low temperatures may be improved.