An on-line State of Health estimation method of a battery in a wide temperature range based on “standardized temperature” includes: calculating battery Incremental Capacity curve of a battery, establishing a quantitative relationship between the voltage shift of the temperature-sensitive feature point and the temperature of a standard battery, standardized transformation of Incremental Capacity curves at different temperatures, establishing a quantitative relationship between the transformed height of the capacity-sensitive feature point and the State of Health based on a BOX-COX transformation. The BOX-COX transformation is expressed as y k ( λ ) = { y k λ - 1 λ λ ≠ 0 ln ⁢ ⁢ y k λ = 0 . An maximum likelihood function is used to calculate the optimal λ, and the transformed height of the capacity-sensitive feature point y can be acquired. The quantitative relationship between transformed height of the capacity-sensitive feature point and the State of Health is established to obtain the State of Health.