Height adjustment device of wheelchair seat with shock absorber

The present invention relates to a height adjustment device of a wheelchair seat. According to the present invention, in a height adjustment device of a wheelchair seat combined with a shock absorber, installed in a wheelchair (1) to vertically move a seat unit (100) including a cushion on which a user sit, the seat unit (100) comprises: an upper plate having the cushion formed on an upper surface; a lower plate (20) installed in the lower part of the upper plate (10) by being spaced apart at a predetermined interval; a height adjustment unit (30) installed in the lower plate (20) to lift/lower the upper plate (10); and an operation unit (70) to operate the height adjustment unit (30). Thus, since a structure of a seat height adjustment device of a wheelchair is simple, easy usage is provided to a user. Moreover, since the seat unit includes the shock absorber and a tensile spring, good ride comfort is provided even if the ground is uneven.