The present invention relates to a method for manufacturing a turbomachine rectifier comprising an outer ring (5) and a plurality of stator vanes (2), said vanes comprising a platform (9) and a blade (12), wherein said method comprises at least the following steps: a) first folds (7) are draped over a core comprising perforations and having the shape of the aerodynamic flow; b) optionally, the first folds (7) are cut along incisions (8) placed opposite the perforations of the core; c) the blades (12) of the vanes or, alternatively, the blades (12) of the vane preforms, are inserted through the incisions (8) of the first folds (7) and through the perforations of the core; d) last folds (10) are draped over the platforms (9) thus forming a rectifier preform; e) a resin is injected into a closed mold with the preform and the resin-impregnated preform is polymerized; f) a molded piece, essentially having the shape and dimensions of said rectifier, is retrieved from the mold.