Flexible pressure sensors have been widely explored for use in versatile applications in electronic skins and wearable healthcare monitoring devices. For these applications, there are several challenges such as high sensitivity, linearity and simply fabrication process. Here, we suggest highly sensitive flexible pressure sensors based on simple spray coating of sea-urchin-shaped polyaniline-silica conductive nanoparticles. The sea-urchin-shaped nanoparticles based on core-shell structures of spherical silica nanoparticles decorated with conductive polyaniline shells. The spray coating of nanoparticles enables uniform formation of conductive films, which can be used as highly-sensitive piezoresistive pressure sensors when two films are put together into a bilayer structure. Our pressure sensors exhibit high sensitivity (12 kPa-1) and linearity in wide pressure regimes (50 Pa – 120 kPa) due to the tip enhanced electric field effect and difference of their surface area, respectively.