The invention discloses a novel umbrella-shaped anti-bird thorn capable for maintaining the opening angle of a thorn and a preparation method. The thorn includes a top thorn needle, a thorn needle withdrawing device, a plurality of anti-bird thorn needles, a thorn needle support part and a bottom fixed part which is clamped on an angle steel of a power transmission mast. The thorn needle support part includes a main rod and opening parts. The lower end of the main rod is welded to the bottom fixed part through a base compression-jointing part. The anti-bird thorn needles in different lengths are wrapped around the external portion of the upper end of the main rod. Furthermore, the upper end of the main rod is connected into the lower end of the thorn needle withdrawing device in a pressedmode. A plurality of main rod sliding rings evenly distributed are arranged on the main rod. The two sides of each main rod sliding ring are symmetrically provided with the opening parts of which oneends are connected with the main rod sliding rings. The other ends of the opening parts are connected with the anti-bird thorn needles. The upper end of the thorn needle withdrawing device is fixedlyconnected with the top thorn needle. According to the novel umbrella-shaped anti-bird thorn capable for maintaining the opening angle of the thorn and a preparation method, the anti-bird effect is ensured. Besides, the opening angle of the anti-bird thorn is maintained at the same time, and safer anti-bird measures are provided for electric transmission line running.