Abstract: Combing the advantages of the compact spinning with Siro spinning,compact sirospun yarn possesses good performances of both the compact yarn and two-ply yarn,such as high strength,less hairy,compact structure and high abrasion resistance.The principle and features of the compact Siro spinning technology are introduced in this paper.Several profile suction pipes with different double slots are developed and applied to spin cotton yarns of same fineness.Though comparing the structure and performance of this cotton yarn with that of yarns by the compact spinning or the Siro spinning,the advantages of compact Siro spinning are further indicated.Finally,the results of these suction slots are evaluated by fuzzy mathematics,and the suction installation by which yarns with the best comprehensive performances are spun is selected.