Silver nanowire (AgNW) films are prepared by using the spin-coating technique and processed by solvent vapor annealing. The sheet resistance, transmissivity, microstructures and surface morphologies of AgNW films are investigated. The current-voltage characteristics of the polymer solar cells with these annealed AgNW films as the anodes are analyzed. The results show that, after 3 h of methanol annealing treatment, the sheet resistance of these films decreases from 45.3 Ω/□ before annealing to 28.7 Ω/□, and finally saturates. The quality factor increases by 72.7% and the properties of films are improved. With the increase of the boiling point of the alcoholic solvent, the decrease of the sheet resistance of AgNW films becomes slow. The photoelectric conversion efficiency of polymer solar cells with these annealed AgNW films as anodes increases from 0.94% before annealing to 1.60%. The AgNW films with superior properties can be obtained after 3 h of annealing treatment.