PURPOSE: To have stable yarn splicing by simultaneously operating clamp cutters of one-side yarn guides and the outer side yarn guides of No.1, No.2 splicers.

CONSTITUTION: When two yarns are to be spliced, element yarns 10, 11 obtained by separating a two-folded yarn 9 on the supply side are led to one-side yarn guides of No.1, No.2 splicers 1, 2, while element yarns 7, 8 obtained by separat ing a two-folded yarn 6 on the takeup side are introduced to the other side yarn guides of the splicers 1, 2. Clamp cutters 17, 18 and 19, 20 furnished on on-side yarn guides and the other side yarn guides of these splicers 1, 2 clamp the element yarns 7, 8, 10, 11 fed to the splicers 1, 2, and are operated after a certain while. Because the cutters are interlocking, the element yarns are cut simultaneously. Thereby the lengths at the opened yarn end can be made equal, which ensures that splicing is performed stably.