The invention discloses a spinning method of double-core-spun colorful allochromatic half slub yarn.The spinning method includes following steps: preparing yarn including eight fiber strips A, B, C, D, G, H, M and N: spinning yarn into cotton strips through processes of blowing, cotton carding and combing, combing the yarn, and spinning to obtain fiber strips E, F, O and P; spinning X rough yarn, Y rough yarn, fine yarn and a spool.The double-core-spun colorful allochromatic half slub yarn is unique in structure, various mixing technologies, long filament core-spun composite technology and spinning technology of slub yarn, Siro spinning and fancy yarn are combined, the yarn which is complementary in performance, changeable in color and unique in style is formed, and more options are provided for innovation and development of fabric.