Preparation method for ethylene-vinyl alcohol copolymer

A method for preparing ethylene-vinyl alcohol copolymer, comprising:

• a first saponification reaction step wherein a first saponification reaction is performed while adding a first alkali catalyst solution dropwise to ethylene-vinyl acetate copolymer dispersed in an alcohol solvent, and a first saponification reaction mixture is obtained after the first saponification reaction step is completed;
• and
• a second saponification reaction step wherein a second saponification reaction is performed while adding a second alkali catalyst solution dropwise to the first saponification reaction mixture,
• wherein a total amount of the first alkali catalyst and second alkali catalyst used are 0.01 moles or more to less than 0.03 moles, based on 1 mole of vinyl acetate unit of the ethylene-vinyl acetate copolymer,
• the first saponification reaction step is completed when the dropwise addition of the first alkali catalyst solution is completed, and
• the second saponification reaction step is completed when the dropwise addition of the second alkali catalyst solution is completed.