The invention discloses a method for spinning medium-top grade pure linen yarns with scotched flax, which uses the scotched flax as raw materials, and is used for spinning the medium-top grade pure linen yarns by means of improvement of existing technological equipment and technological parameters. The method is mainly characterized by including the steps of increasing the needling density of heckling fallers, increasing drawing times and the faller gill density, strictly controlling the twisting coefficient and winding density of rough yarns, adopting organic boiling off and secondary bleaching, strictly controlling spun yarn twisting coefficient and spindle rotating speed, keeping proper drying temperature and drying time, and controlling groove drum rotating speed and tension piece weight. The method for spinning the medium-top grade pure linen yarns with the scotched flax has the advantages that the method is reasonable in technology, the technological equipment is improved simply, and the quality of the medium-top grade pure linen yarns spun by the scotched flax reaches quality standard and the like. The method opens up a new approach for spinning the medium-top grade pure linen yarns with inferior scotched flax.