A pressure sensing device includes an elastic tube defming a chamber and an opening in one or each of two opposite ends thereof in communication with the chamber, and a pressure sensor component sealed in the opening in one or each end of the elastic tube for detecting a change in air pressure in the chamber when the elastic tube is compressed by an external pressure. The pressure sensing device can be used under a waterproof or dustproof environment, or embedded in a bed mattress or seat cushion and incorporated with a signal processor for detecting changes in the biophysical condition of the user, or embedded in a floor mat and incorporated with light and/or sound generating device for reminding your home or store that someone is coming in or going out. Thus, the pressure sensing device has the characteristics of simple structure, practical applicability and wide application range.
