Method of manufacturing a turbomachine blade (100) made of composite material, comprising a fibrous reinforcement consolidated by a matrix, the method involving: - creating a multilayer woven fabric so as to obtain a first fibrous preform (1) in a single piece, said first preform (1) comprising a first part (2) forming the blade root preform and extended by a second part (3) having a thickness smaller than the thickness of the first part (2), said second part (3) forming a stub preform, - creating a multilayer woven fabric so as to obtain a second fibrous preform (4; 14; 14') in a single piece, said second preform (4; 14; 14') comprising a first part (5; 15; 15') formed of two skins (5a; 5b; 15a; 15b; 15'a; 15'b) between them delimiting an internal housing (6), said first part (5; 15; 15') forming a blade air foil preform, and at least a second part (7; 17; 17') extending from the external surface of said skins (5a; 5b; 15a; 15b; 15'a; 15'b), said at least second part (7; 17; 17') forming a platform preform, - the assembly of the first preform (1) in the consolidated or non-preconsolidated state with the second form (4; 14; 14') in the non-consolidated state by engagement of the second part (3) of the first preform (1) into the internal housing (6) of the first part (5; 15; 15') of the second preform (4; 14; 14'), and - the codensification of the first (1) and second (4; 14; 14') preforms thus assembled in order to obtain a turbomachine blade (100).