A pressure sensing device is disclosed in the present disclosure. The pressure sensing device includes a bottom plate, a flexible shell and a MEMS pressure sensor. The flexible shell covers the bottom plate for forming a hermetical cavity, and the MEMS pressure sensor is accommodated in the hermetical cavity. Air in the hermetical cavity is compressed when the flexible shell is pressed, the MEMS pressure sensor is configured for detecting variation of an air pressure within the hermetical cavity when the flexible shell is pressed, and convert the variation of the air pressure into an electric signal.