A method for producing a transformable dry preform, in particular for the creation of a product made of composite materials, includes the sequence of the following steps: simultaneous weft/wale knitting of at least one stitch thread and at least one unidirectional reinforcement thread, at least one stitch thread including a material, the nature of which being different to that of a material comprised in at least one unidirectional reinforcement thread, at least one of the materials being thermoplastic and having a melting point lower than the melting point of at least one other material, referred to as reinforcement material; and creating of a three-dimensional knit that constitutes a dry preform in the shape of the product that is to be obtained. Additionally, a product made of composite materials can be produced using the dry preform created by the method.