A method for preparing chiral synthetic nicotine, characterized by comprising the following steps: Step S 1. condensing nicotinic acid ester and γ-butyrolactone under the action of alkaline condensate in organic solvent I to obtain a first mixture; Step S2. performing a ring-opening reaction to the first mixture obtained in Step S1 by adding an acidic substance to obtain a second mixture; Step S3. separating 4-chloro-1-(3-pyridine)-1-butanone from the second mixture obtained in Step S2, reacting 4-chloro-1-(3-pyridine)-1-butanone with chiral tert-butyl sulfinamide in organic solvent II and titanate to obtain a third mixture containing chiral n-(4-chloro-1-(pyridin-3-yl)butene)-2-methylpropane-2-sulfinamide, filtering, extracting, and removing the solvent to obtain chiral n-(4-chloro-1-(pyridin-3-yl)butene)-2-methylpropane-2-sulfenamide; Step S4: dissolving the chiral n-(4-chloro-1-(pyridin-3-yl)butene)-2-methylpropane-2-sulfenamide obtained in Step S3 in organic solvent III, reacting with a reducing agent, and then cyclizing under the action of hydrogen halide to obtain a fourth mixture; and Step S5: reacting the fourth mixture obtained in Step S4 with a methylamination reagent to obtain a fifth mixture, and purifying the fifth mixture to obtain the chiral synthetic nicotine; wherein in Step S3, the organic solvent II is one or more selected from a group consisting of anhydrous tetrahydrofuran, dimethyltetrahydrofuran and 1,4-dioxane; in Step S3, a reaction temperature of the 4-chloro-1-(3-pyridine)-1-butanone and chiral tert-butyl sulfenamide is 70-90°C, with a reaction time of 5-8h; in Step S1, the molar ratio of nicotinic acid ester, γ-butyrolactone, and alkaline condensate is 1:: (1.2-3); and in Step S1, the alkaline condensate is one or more selected from a group consisting of alkali metal alkoxide, alkaline earth metal hydride, alkaline earth metal oxide, amine, metal salt of amines, hydroxide, carbonate and bicarbonate. Step S 1. condensing nicotinic acid ester and γ-butyrolactone under the action of alkaline condensate in organic solvent I to obtain a first mixture; Step S2. performing a ring-opening reaction to the first mixture obtained in Step S1 by adding an acidic substance to obtain a second mixture; Step S3. separating 4-chloro-1-(3-pyridine)-1-butanone from the second mixture obtained in Step S2, reacting 4-chloro-1-(3-pyridine)-1-butanone with chiral tert-butyl sulfinamide in organic solvent II and titanate to obtain a third mixture containing chiral n-(4-chloro-1-(pyridin-3-yl)butene)-2-methylpropane-2-sulfinamide, filtering, extracting, and removing the solvent to obtain chiral n-(4-chloro-1-(pyridin-3-yl)butene)-2-methylpropane-2-sulfenamide; Step S4: dissolving the chiral n-(4-chloro-1-(pyridin-3-yl)butene)-2-methylpropane-2-sulfenamide obtained in Step S3 in organic solvent III, reacting with a reducing agent, and then cyclizing under the action of hydrogen halide to obtain a fourth mixture; and Step S5: reacting the fourth mixture obtained in Step S4 with a methylamination reagent to obtain a fifth mixture, and purifying the fifth mixture to obtain the chiral synthetic nicotine; wherein in Step S3, the organic solvent II is one or more selected from a group consisting of anhydrous tetrahydrofuran, dimethyltetrahydrofuran and 1,4-dioxane; in Step S3, a reaction temperature of the 4-chloro-1-(3-pyridine)-1-butanone and chiral tert-butyl sulfenamide is 70-90°C, with a reaction time of 5-8h; in Step S1, the molar ratio of nicotinic acid ester, γ-butyrolactone, and alkaline condensate is 1:: (1.2-3); and in Step S1, the alkaline condensate is one or more selected from a group consisting of alkali metal alkoxide, alkaline earth metal hydride, alkaline earth metal oxide, amine, metal salt of amines, hydroxide, carbonate and bicarbonate.