A secondary battery static pressure jig, comprising: a supporting member disposed on both surfaces of a battery cell to support the battery cell; a piezoelectric element that is disposed on at least one of surfaces of the supporting member and the battery cell contacting each other and measures a pressure applied to the battery cell; and a controlling part that controls a volume of the piezoelectric element according to the pressure measured by the piezoelectric element, wherein a volume of the piezoelectric element is changed according to the volume change of the battery cell, and the pressure applied to the battery cell from the supporting member by the volume change of the piezoelectric element is made to be a constant pressure, wherein the controlling part includes a converting part that converts a pressure value measured by the piezoelectric element into a first voltage signal; a calculating part that calculates a second voltage signal for changing the battery cell to an initial pressure state using the first voltage signal; and a driving part that drives the piezoelectric element according to the second voltage signal, wherein the supporting member includes a first supporting part contacting an upper surface of the battery cell; and a second supporting part contacting a lower surface of the battery cell, the secondary battery static pressure jig further includes a coupling part that penetrates the supporting member and couples the first supporting part and the second supporting part to each other, the coupling part is movably coupled according to a change in the pressure applied to the battery cell according to a change in the volume of the piezoelectric element. a supporting member disposed on both surfaces of a battery cell to support the battery cell; a piezoelectric element that is disposed on at least one of surfaces of the supporting member and the battery cell contacting each other and measures a pressure applied to the battery cell; and a controlling part that controls a volume of the piezoelectric element according to the pressure measured by the piezoelectric element, wherein a volume of the piezoelectric element is changed according to the volume change of the battery cell, and the pressure applied to the battery cell from the supporting member by the volume change of the piezoelectric element is made to be a constant pressure, wherein the controlling part includes a converting part that converts a pressure value measured by the piezoelectric element into a first voltage signal; a calculating part that calculates a second voltage signal for changing the battery cell to an initial pressure state using the first voltage signal; and a driving part that drives the piezoelectric element according to the second voltage signal, wherein the supporting member includes a first supporting part contacting an upper surface of the battery cell; and a second supporting part contacting a lower surface of the battery cell, the secondary battery static pressure jig further includes a coupling part that penetrates the supporting member and couples the first supporting part and the second supporting part to each other, the coupling part is movably coupled according to a change in the pressure applied to the battery cell according to a change in the volume of the piezoelectric element. <EOS>