The invention discloses a device capable of adjusting silken surface breadth of a rapier loom. The device comprises a creel base, long rods, a breadth separator, a fastener, and a creel connecting rod, wherein the creel base is used for installing creels, a connecting frame is fixedly connected with the creel base, the long rods are arranged above the creel base through the connecting frame in the horizontal direction, the breadth separator is arranged on the long rods in a penetrating mode, and can slide in the rod diameter direction of the long rods; the fastener is used for being fixedly connected with the breadth separator and the long rods, and the creels are connected with the breadth separator through the creel connecting rod. According to the device capable of adjusting the silken surface breadth of the rapier loom, two long rods are installed on an original separating device, the long rods are connected with the breadth separator, according to a breadth requirement, the breadth separator can move back and forth in the rod diameter of the long rods, and the breadth can be freely adjusted according to a production requirement.