A yarn joining processing device for connecting a yarn end of a first yarn feeding package mounted on a yarn feeding stand to a yarn end of a second yarn feeding package and locking a connected yarn to at least one locking portion provided in the yarn feeding stand, the yarn joining processing device comprising: a suction holding portion which sucks the yarn and holds the yarn; a moving portion which moves the suction holding portion; a connecting portion which connects the yarn end of the first yarn feeding package to the yarn end of the second yarn feeding package; and a control unit which controls the suction holding portion, the moving portion, and the connecting portion, wherein the control unit controls the suction holding portion, the moving portion, and the connecting portion so as to perform a yarn joining process including a first setting operation of holding the yarn end of the first yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to set the yarn end of the first yarn feeding package to the connecting portion, a second setting operation of holding the yarn end of the second yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to set the yarn end of the second yarn feeding package to the connecting portion, and a connecting operation of connecting the yarn end of the first yarn feeding package to the yarn end of the second yarn feeding package by the connecting portion after the first setting operation and the second setting operation, and wherein the control unit controls the suction holding portion and the moving portion to perform a yarn hooking process including at least one of a first yarn hooking operation of holding the yarn end of the first yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to lock the yarn of the first yarn feeding package to the locking portion before the first setting operation and a second yarn hooking operation of holding the yarn end of the second yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to lock the yarn of the second yarn feeding package to the locking portion before the second setting operation. a suction holding portion which sucks the yarn and holds the yarn; a moving portion which moves the suction holding portion; a connecting portion which connects the yarn end of the first yarn feeding package to the yarn end of the second yarn feeding package; and a control unit which controls the suction holding portion, the moving portion, and the connecting portion, wherein the control unit controls the suction holding portion, the moving portion, and the connecting portion so as to perform a yarn joining process including a first setting operation of holding the yarn end of the first yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to set the yarn end of the first yarn feeding package to the connecting portion, a second setting operation of holding the yarn end of the second yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to set the yarn end of the second yarn feeding package to the connecting portion, and a connecting operation of connecting the yarn end of the first yarn feeding package to the yarn end of the second yarn feeding package by the connecting portion after the first setting operation and the second setting operation, and wherein the control unit controls the suction holding portion and the moving portion to perform a yarn hooking process including at least one of a first yarn hooking operation of holding the yarn end of the first yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to lock the yarn of the first yarn feeding package to the locking portion before the first setting operation and a second yarn hooking operation of holding the yarn end of the second yarn feeding package by the suction holding portion and moving the suction holding portion by the moving portion so as to lock the yarn of the second yarn feeding package to the locking portion before the second setting operation.