The invention discloses an automatic down feather water washing device and method. The down feather water washing device comprises a base, the top of the base is provided with a mounting groove, the mounting groove is internally and slidably provided with a mounting plate, the top of the mounting plate extends into the upper portion of the base, the top of the mounting plate is provided with a water washing device body, the bottom of the water washing device body is fixedly provided with a placing block, the top of the mounting plate is provided with a placing groove, the placing block is in clamped connection with the placing groove, the inner walls of the two sides of the placing groove are both provided with moving grooves of which top portions are provided with openings, the moving grooves are internally and slidably provided with moving plates, the sides, close to each other, of the two moving plates are both fixedly provided with fixing blocks, and two sides of the placing blockare both provided with fixing grooves. The automatic down feather water washing device and method have the advantages that the water washing device body can be installed and fixed conveniently, damping of the water washing device body can be achieved conveniently, the noise can be reduced, the components and parts in the water washing device body can be protected conveniently, the structure is simple, and the use is convenient.