An indicator assembly of a supporting leg device for a safety seat, comprising: an indicator housing positioned at an upper end of the supporting leg device and having an indicator window that is formed by penetrating through the indicator housing; an indicating member including a first area and a second area which are adjacent to each other and have different colors or patterns, the indicating member being pivotally accommodated in the indicator housing so that the first area and the second area can be alternatively exposed from the indicator window; a first elastic member disposed in the indicator housing and driving the indicating member to pivot to a first position along a first direction; a pushing member extending in a longitudinal direction of the supporting leg device inside the supporting leg device, being movable vertically, and having a plurality of engaging holes arranged longitudinally, and a top end of the pushing member capable of pushing the indicating member to pivot to a second position in a second direction opposite to the first direction; a driving member extending in a longitudinal direction of the supporting leg device inside the supporting leg device, being movable vertically, and including an upper end provided with an engaging hook and a lower end capable of touching a floor, in which the engaging hook is operably engaged into one of the plurality of engaging holes of the pushing member; wherein, when the lower end of the driving member does not touch the floor, the indicating member pivots to the first position in the first direction under the acting force of the first elastic member such that the first area is exposed from the indicating window; and when the lower end of the driving member touches the floor, the driving member drives the pushing member to move upward by means of the engagement of the engaging hook and the engaging hole, thus the top end of the pushing member pushes the indicating member and overcomes the acting force of the first elastic member and pivots to the second position in the second direction, so that the second area is exposed from the indicating window. an indicator housing positioned at an upper end of the supporting leg device and having an indicator window that is formed by penetrating through the indicator housing; an indicating member including a first area and a second area which are adjacent to each other and have different colors or patterns, the indicating member being pivotally accommodated in the indicator housing so that the first area and the second area can be alternatively exposed from the indicator window; a first elastic member disposed in the indicator housing and driving the indicating member to pivot to a first position along a first direction; a pushing member extending in a longitudinal direction of the supporting leg device inside the supporting leg device, being movable vertically, and having a plurality of engaging holes arranged longitudinally, and a top end of the pushing member capable of pushing the indicating member to pivot to a second position in a second direction opposite to the first direction; a driving member extending in a longitudinal direction of the supporting leg device inside the supporting leg device, being movable vertically, and including an upper end provided with an engaging hook and a lower end capable of touching a floor, in which the engaging hook is operably engaged into one of the plurality of engaging holes of the pushing member; wherein, when the lower end of the driving member does not touch the floor, the indicating member pivots to the first position in the first direction under the acting force of the first elastic member such that the first area is exposed from the indicating window; and when the lower end of the driving member touches the floor, the driving member drives the pushing member to move upward by means of the engagement of the engaging hook and the engaging hole, thus the top end of the pushing member pushes the indicating member and overcomes the acting force of the first elastic member and pivots to the second position in the second direction, so that the second area is exposed from the indicating window.