The invention discloses a high-conductivity PEDOT:PSS self-supporting thick film, a preparation method and applications thereof, and belongs to the field of electric-conducting polymer materials. Thepreparation method comprises: adding an organic doping agent into a PEDOT:PSS aqueous solution, preparing a uniform mixed solution while stirring, coating a cleaned glass sheet in a dropwise manner with the mixed solution, and drying to form a film; cooling the obtained film, soaking in water, and stirring; and taking the film out of the water, and drying to obtain the high-conductivity PEDOT:PSSself-supporting thick film, wherein the thickness of the film is 2-20 [mu]m. According to the invention, the conductivity of the prepared thick film is improved by more than 1000 times compared with the intrinsic PEDOT:PSS film; and the high-conductivity PEDOT:PSS self-supporting thick film does not need a substrate, the preparation method is simple, the cost is low, the thickness has excellent adjustability, and the high-conductivity PEDOT:PSS self-supporting thick film has excellent flexibility, and has great development potential and application value in the fields of flexible electronics,thermoelectric materials and the like.