Abstract: A method for performing a real-time response hydrogen-charging process in a hydrogen-charger may comprise the steps of: calculating a pressure loss coefficient value in a charging line to be applied to a real case; calculating the inner diameter value of the charging line to be applied to the real case, on the basis of the calculated pressure loss coefficient value, a preset reference pressure loss coefficient value in a reference case, and a preset inner diameter value of a reference charging line in the reference case; and performing the hydrogen-charging process by applying the calculated inner diameter value of the charging line to a predetermined thermodynamic model for real-time hydrogen-charging in the real case.