Recently, a lot of research has been conducted to measure small pressure regimes (1-10 kPa) with the purpose of detecting wrist pulse and develop human-machine interfaces. In this work, we report a highly sensitive and flexible piezo-capacitive pressure sensor based on a porous dielectric matrix containing multi-walled carbon nanotubes (MWNTs) as conductive fillers. Porous dielectric matrix containing conductive fillers has a high resolution because the conductive fillers increase the dielectric constant of the matrix. This difference leads to a high sensitivity. Although this sensor has good performances, it is vulnerable to environmental interferes such as the human hand and electromagnetic signals. Therefore, we applied shielding systems to the fabricated sensor. Additionally, temperatures and air humidity have little influence on the output signal of the sensor.