The invention relates to a knitting yarn switching method and a knitting yarn switching device. When knitting yarns from yarn cones (12b, 12a) are fed to yarn feeders (13b, 14a), end portions of the knitting yarn fed to the yarn feeders (14b, 13a) are held, and when knitting yarns from the yarn cones (12b, 12a) are fed to the yarn feeders (14b, 13a), end portions of the knitting yarns fed to the yarn feeders (13b, 14a) are held. The knitting yarns to be connected thus held and the yarn cones (12b, 12a) are pieced into each other, and thereafter, holding of the end portions of the knitting yarns to be connected is released, and the knitting yarns fed from the yarn cones (12b, 12a) are cut between the pieced portions of the knitting yarns to be connected and portions reaching the yarn feeders, and the end portions of the knitting yarns cut off from the yarn cones (12b, 12a) are held.