The invention discloses a method for preparing a flexible N type silver telluride nanowire thermoelectric thin film. The method includes the following steps: mixing a silver telluride nanowire with polyvinylpyrrolidone, and performing ultrasonic dispersion of the mixture in a solvent to obtain a silver telluride nanowire dispersion liquid; under the condition of vacuum filtration, uniformly dripping the silver telluride nanowire dispersion liquid on a glass fiber filter membrane, and performing vacuum drying at 75 DEG C to obtain a silver telluride nanowire thin film adhered to the glass fiber filter membrane; clamping the silver telluride nanowire thin film between two pieces of copy paper, placing the whole in a tablet press to perform extrusion forming, then using a brush to remove glass fiber filter membrane fragments on the reverse side of the silver telluride nanowire thin film, and placing the silver telluride nanowire thin film in a vacuum oven for annealing to obtain a target product. The method for preparing the flexible N type silver telluride nanowire thermoelectric thin film is simple and controllable, short in preparation cycle, safe and pollution-free, and low in energy consumption, an obtained thin film has excellent thermoelectric performance and good flexibility, flexible thermoelectric thin films of different sizes and shapes can be prepared flexibly according to the sizes and shapes of glass fiber membranes, and thus the method has wide application prospects.