A method for manufacturing a turbine nozzle vane made of ceramic matrix composite material, the method comprising: - the provision of a first fibrous preform comprising (i) a hollow central section (11; 110) intended to form a fibrous reinforcement of an airfoil of the vane to be obtained, (ii) an internal lateral section extending from an internal portion of the central section on each side thereof and transversely thereto, and (iii) an external lateral section extending from an external portion of the central section on each side thereof and transversely thereto, - the provision of a pair of second fibrous preforms (20a; 20b) each having an opening (201a; 201b) with a shape of the airfoil of the vane to be obtained that opens out onto a first edge (21a; 21b) of the second fibrous preform considered, each second fibrous preform having two skins (23a-25a; 23b-25b) bonded on a second edge (27a; 27b) of the second fibrous preform considered, distinct from the first edge, these skins defining unbonded areas on either side of the opening as to be able to be spaced apart from each other, - the assembly of one of the second fibrous preforms with the first fibrous preform by insertion of the central section into the opening of the second fibrous preform considered and by positioning of the internal lateral section between the skins of the second fibrous preform considered, this assembly being intended to form a fibrous reinforcement of an internal platform of the vane to be obtained, - the assembly of the other of the second fibrous preforms with the first fibrous preform by insertion of the central section into the opening of the second fibrous preform considered and by positioning of the external lateral section between the skins of the second fibrous preform considered, this assembly being intended to form a fibrous reinforcement of an external platform of the vane to be obtained, and - the securing of the second preforms thus assembled to the first preform by formation of a common ceramic matrix between these preforms. - the provision of a first fibrous preform comprising (i) a hollow central section (11; 110) intended to form a fibrous reinforcement of an airfoil of the vane to be obtained, (ii) an internal lateral section extending from an internal portion of the central section on each side thereof and transversely thereto, and (iii) an external lateral section extending from an external portion of the central section on each side thereof and transversely thereto, - the provision of a pair of second fibrous preforms (20a; 20b) each having an opening (201a; 201b) with a shape of the airfoil of the vane to be obtained that opens out onto a first edge (21a; 21b) of the second fibrous preform considered, each second fibrous preform having two skins (23a-25a; 23b-25b) bonded on a second edge (27a; 27b) of the second fibrous preform considered, distinct from the first edge, these skins defining unbonded areas on either side of the opening as to be able to be spaced apart from each other, - the assembly of one of the second fibrous preforms with the first fibrous preform by insertion of the central section into the opening of the second fibrous preform considered and by positioning of the internal lateral section between the skins of the second fibrous preform considered, this assembly being intended to form a fibrous reinforcement of an internal platform of the vane to be obtained, - the assembly of the other of the second fibrous preforms with the first fibrous preform by insertion of the central section into the opening of the second fibrous preform considered and by positioning of the external lateral section between the skins of the second fibrous preform considered, this assembly being intended to form a fibrous reinforcement of an external platform of the vane to be obtained, and - the securing of the second preforms thus assembled to the first preform by formation of a common ceramic matrix between these preforms.