The utility model discloses a needle core movement mechanism for a full-width weft insertion machine. The needle core movement mechanism comprises a machine body, a connecting rod frame, a transmission piece and a pendulum shaft seat, wherein a main shaft is rotatably supported on the connecting rod frame, an eccentric wheel is installed on the main shaft so that the eccentric wheel can be drivento rotate through rotation of the main shaft, the eccentric wheel is sleeved with an eccentric sleeve, and a rolling bearing is arranged between the eccentric wheel and the eccentric sleeve; a first connecting rod and a third connecting rod are hinged to the connecting rod frame, one end of the first connecting rod is hinged to the eccentric sleeve, the other end of the first connecting rod is hinged to one end of the third connecting rod through a second connecting rod, and the other end of the third connecting rod is hinged to one end of the transmission piece; a swing shaft is arranged on the swing shaft seat, a swing arm is rotatably sleeved on the swing shaft, a needle core is mounted on the swing arm, and the other end of the transmission part is hinged with the swing arm. The movement speed and the movement stability of the needle core are greatly improved, the structure is simple, and implementation is easy.