A splice holder, comprising a substrate and at least two retaining plates disposed on the substrate, wherein there are at least two retaining plates disposed opposite to each other in the at least two retaining plates, to form at least one accommodating area configured to accommodate a first splice protection sleeve; for any accommodating area, at least one first flexible arm is disposed on a first one of the at least two retaining plates that form the accommodating area, and the at least one first flexible arm bends towards the at least one accommodating area when in a natural state; a stopper is further disposed on a top end of a second one of the at least two retaining plates that form the at least one accommodating area, the second retaining plate being opposite to the first retaining plate, and wherein the top end is away from the substrate; and when the first splice protection sleeve is installed in the at least one accommodating area, the at least one first flexible arm is elastically deformed and secures the first splice protection sleeve in the at least one accommodating area under the action of an elastic force, and the stopper is configured to restrict movement of the first splice protection sleeve in a direction away from the substrate; wherein at least one second flexible arm is further disposed on the first retaining plate, the at least one second flexible arm bends towards the at least one accommodating area when in a natural state, there is a gap between the at least one second flexible arm and the substrate, and when the at least one second flexible arm is in the natural state, a bottom surface that is of the at least one second flexible arm and that faces the substrate is configured to restrict movement of the first splice protection sleeve in a direction away from the substrate; wherein one accommodating area of the least one accommodating area is further configured to secure at least one second splice protection sleeve, and the first and at least one second splice protection sleeves are sequentially arranged vertically in the direction perpendicular to the substrate, the at least one second splice protection sleeve being atop the first splice protection sleeve; and when the first and at least one second splice protection sleeves are installed in the one accommodating area of the at least one accommodating area, the at least one first flexible arm secures each of the splice protection sleeves in the one accommodating area of the at least one accommodating area through elastic deformation, and the at least one second flexible arm secures the at least one second splice protection sleeve in the one accommodating area of the at least one accommodating area through elastic deformation. for any accommodating area, at least one first flexible arm is disposed on a first one of the at least two retaining plates that form the accommodating area, and the at least one first flexible arm bends towards the at least one accommodating area when in a natural state; a stopper is further disposed on a top end of a second one of the at least two retaining plates that form the at least one accommodating area, the second retaining plate being opposite to the first retaining plate, and wherein the top end is away from the substrate; and when the first splice protection sleeve is installed in the at least one accommodating area, the at least one first flexible arm is elastically deformed and secures the first splice protection sleeve in the at least one accommodating area under the action of an elastic force, and the stopper is configured to restrict movement of the first splice protection sleeve in a direction away from the substrate; wherein at least one second flexible arm is further disposed on the first retaining plate, the at least one second flexible arm bends towards the at least one accommodating area when in a natural state, there is a gap between the at least one second flexible arm and the substrate, and when the at least one second flexible arm is in the natural state, a bottom surface that is of the at least one second flexible arm and that faces the substrate is configured to restrict movement of the first splice protection sleeve in a direction away from the substrate; wherein one accommodating area of the least one accommodating area is further configured to secure at least one second splice protection sleeve, and the first and at least one second splice protection sleeves are sequentially arranged vertically in the direction perpendicular to the substrate, the at least one second splice protection sleeve being atop the first splice protection sleeve; and when the first and at least one second splice protection sleeves are installed in the one accommodating area of the at least one accommodating area, the at least one first flexible arm secures each of the splice protection sleeves in the one accommodating area of the at least one accommodating area through elastic deformation, and the at least one second flexible arm secures the at least one second splice protection sleeve in the one accommodating area of the at least one accommodating area through elastic deformation.