A method for producing a lithium difluorophosphate crystal, comprising: step 1 of synthesizing a lithium difluorophosphate crystal from dihalophosphate represented by Chemical Formula 1 below; and step 2 of purifying and recrystallizing the lithium difluorophosphate crystal; and wherein step 1 comprises: step 1-1 of synthesizing difluorophosphate represented by Chemical Formula 2 below by reacting a mixed solution in which dihalophosphate represented by Chemical Formula 1 below, a fluorinating agent, and a non-aqueous solvent are mixed under an inert gas; step 1-2 of adding and reacting the difluorophosphate dropwise to a mixed solution of a lithium salt, water, and a non-aqueous solvent, and then evaporating the non-aqueous solvent to obtain a solid; and step 1-3 of dissolving the solid in a non-aqueous solvent, recrystallizing at 25°C to 0°C, and filtering to obtain a lithium difluorophosphate crystal; and, wherein the mixed solution in step 1-1 comprises dihalophosphate and a fluorinating agent at a molar ratio of 1:2.0 to 3.0, wherein the yield of the lithium difluorophosphate crystal synthesized in step 1 is 82% to 92%, and the purity is 95% to 98%, and wherein the yield of the recrystallized lithium difluorophosphate crystal in step 2 is 80% to 90%, and the purity may be 99.00% to 99.99%: wherein in Chemical Formula 1, X 1 and X 2 are each independently -Cl, -Br, or -I, and R is a C 1 to C 10 straight-chain alkyl group, a C 3 to C 10 branched alkyl group, a C 6 to C 10 cycloalkyl group, or a C 6 to C 20 aryl group, wherein in Chemical Formula 2, R is a C 1 to C 10 straight-chain alkyl group, a C 3 to C 10 branched alkyl group, a C 6 to C 10 cycloalkyl group, or a C 6 to C 20 aryl group, provided that R in Chemical Formula 2 is identical to R in Chemical Formula 1. step 1 of synthesizing a lithium difluorophosphate crystal from dihalophosphate represented by Chemical Formula 1 below; and step 2 of purifying and recrystallizing the lithium difluorophosphate crystal; and wherein step 1 comprises: step 1-1 of synthesizing difluorophosphate represented by Chemical Formula 2 below by reacting a mixed solution in which dihalophosphate represented by Chemical Formula 1 below, a fluorinating agent, and a non-aqueous solvent are mixed under an inert gas; step 1-2 of adding and reacting the difluorophosphate dropwise to a mixed solution of a lithium salt, water, and a non-aqueous solvent, and then evaporating the non-aqueous solvent to obtain a solid; and step 1-3 of dissolving the solid in a non-aqueous solvent, recrystallizing at 25°C to 0°C, and filtering to obtain a lithium difluorophosphate crystal; and, wherein the mixed solution in step 1-1 comprises dihalophosphate and a fluorinating agent at a molar ratio of 1:2.0 to 3.0, wherein the yield of the lithium difluorophosphate crystal synthesized in step 1 is 82% to 92%, and the purity is 95% to 98%, and wherein the yield of the recrystallized lithium difluorophosphate crystal in step 2 is 80% to 90%, and the purity may be 99.00% to 99.99%: step 1-1 of synthesizing difluorophosphate represented by Chemical Formula 2 below by reacting a mixed solution in which dihalophosphate represented by Chemical Formula 1 below, a fluorinating agent, and a non-aqueous solvent are mixed under an inert gas; step 1-2 of adding and reacting the difluorophosphate dropwise to a mixed solution of a lithium salt, water, and a non-aqueous solvent, and then evaporating the non-aqueous solvent to obtain a solid; and step 1-3 of dissolving the solid in a non-aqueous solvent, recrystallizing at 25°C to 0°C, and filtering to obtain a lithium difluorophosphate crystal; and, wherein the mixed solution in step 1-1 comprises dihalophosphate and a fluorinating agent at a molar ratio of 1:2.0 to 3.0, wherein the yield of the lithium difluorophosphate crystal synthesized in step 1 is 82% to 92%, and the purity is 95% to 98%, and wherein the yield of the recrystallized lithium difluorophosphate crystal in step 2 is 80% to 90%, and the purity may be 99.00% to 99.99%: