The invention relates to a molding device and a molding method for fixing down flocculus through a warp knitted net. The molding device comprises a stretching mechanism (2), a down spreading mechanism (3), a spunlacing mechanism (4), a transmission mechanism (5), a fixing mechanism (7) and a work bench (8), wherein the left end of the work bench (8) is connected with a net feeding mechanism (1), the right end of the work bench (8) is connected with a winding mechanism (6) and the middle part of the work bench (8) is connected with the fixing mechanism (7); a fixing block of the fixing mechanism (7) is connected with the stretching mechanism (2), the down spreading mechanism (3), the spunlacing mechanism (4) and the transmission mechanism (5) respectively; the method comprises the following steps of: feeding the warp knitted net (11) by the net feeding mechanism (1); feeding the down flocculus on the warp knitted net (11) through the stretching mechanism (2) and the down spreading mechanism (3); jetting water flow to solidify the down flocculus by the spunlacing mechanism (4); and winding the warp knitted net (11) by the winding mechanism (6). Through the device and the method, thepreparation problem of simple, convenient and effective fixation of the down flocculus is solved.