The utility model discloses a directly-communicated air sac type height adjustment structure, which can adjust the height, softness and hardness as well as shape through inflating and deflating air sacs, is applied for cushion bodies, head rests, neck rests, pillows and the like, and can be attached to a propping part of a user in accordance with ergonomics. The directly-communicated air sac type height adjustment structure comprises at least two air sacs, wherein elastic bodies are respectively arranged in the air sacs, one air sac is provided with an air control unit which is used for controlling the air inflation and deflation of the air sac, corresponding through holes are arranged at the corresponding sides of the air sacs, and joint areas are arranged at the peripheries of the through holes and are jointed with each other; and the air sacs are directly and mutually combined together, other mediums (like air pipes) are not needed to be arranged between the air sacs, air in the air sacs can be directly circulated through commonly using one air control unit only, so the air sacs have the effects of quick air inflation and deflation, convenience for manufacturing and lowered manufacturing cost.