A method for estimating an SOC-OCV profile by degradation of a secondary battery according to an embodiment of the present disclosure includes individually obtaining an SOC-OCV profile (a first profile) of a cathode of the secondary battery and an SOC-OCV profile (a second profile) of an anode of the secondary battery using a half cell; obtaining a new SOC-OCV profile (a third profile) of the cathode by reflecting a level of degradation (a %) by use of the secondary battery to modify the SOC-OCV profile of the cathode, but setting only an SOC range to be narrow in proportion to the level of degradation while maintaining an OCV range of the cathode as it is; obtaining a new SOC-OCV profile (a fourth profile) of the anode by migrating the SOC-OCV profile of the anode in a horizontal direction taking into account the level of degradation by use of the secondary battery; and obtaining a new SOC-OCV profile (a fifth profile) by determining a subtraction of an OCV value by the SOC-OCV profile of the anode from an OCV value by the SOC-OCV profile of the cathode as an OCV value of the secondary battery.