The invention discloses a 
pressure sensor based on an 
organic field effect transistor and a preparation method thereof. The 
pressure sensor based on the 
organic field effect transistor comprises a substrate arranged at the lowest layer, wherein a gate 
electrode is arranged on the surface of the substrate, a 
dielectric layer is arranged on the upper surface of the substrate and the gate 
electrode,a 
semiconductor layer is arranged on the upper surface of the 
dielectric layer, a source 
electrode and a drain electrode are arranged on the 
semiconductor layer respectively, and an encapsulation layer is also arranged on the substrate and wraps the gate electrode, the 
dielectric layer, the 
semiconductor layer, the source electrode and the drain electrode inside, wherein the 
dielectric layer is made from a mixed material of bamboo 
cellulose and a biological dielectric material, content of bamboo 
cellulose is 50-75%, the semiconductor layer is made from a mixed material of bamboo fibers and a soluble biological semiconductor material, and 
cellulose content is 5-15%. The 
pressure sensor disclosed by the invention has the advantages that the bamboo cellulose can detect pressure with high sensitivity and high response, the 
dielectric layer doped with the bamboo cellulose and an 
organic semiconductor layer enable device stability to be higher and the pressure sensor device to be more environment-friendly, the preparation method and technology are easy to realize, a biological material functional layer can be well compatible, and environmental 
pollution in a preparation process is reduced.