A blood pressure measuring device comprises an outer case, a display unit, and a pressurized unit. The display unit includes: a base board； a hollow transparent tube installed on the base board； a sealing element closely and fixedly installed at inner rim of the transparent tube； a surrounding element foldably and tightly connected at the top of the sealing element； a top lid tightly installed at the end of the surrounding element opposite to the sealing element； and an elastic element whose two ends individually fixedly connect to the sealing element and the top lid. Wherein, the sealing element, the surrounding element, and the top lid mutually cooperate to define an independent chamber. While the inflation bulb of the pressurized unit is compressed, the air will be squeezed into the chamber to push the top lid for overcoming the elasticity of the elastic element so that it can upwards move within the action area to read the blood pressure.一種血壓量測裝置，包含一外盒、一顯示單元及一加壓單元。該顯示單元包括一基板、一連結於該基板上之中空透明管、一封閉地固設於該透明管內緣之封閉件、一可收合地密接設置於該封閉件頂面的環繞件、一密合設置於該環繞件相反於該封閉件之一端的頂蓋，及一兩端分別固接於該封閉件與該頂蓋的彈性件，其中，該封閉件、環繞件，與頂蓋是相配合而界定出一個獨立的容室。當擠壓該加壓單元之唧球會將空氣擠入該容室，以推動該頂蓋克服該彈性件的彈力而在該作動區內向上移動，進行血壓的判讀。
