A high-reliability elastic soft-sealed gate valve, including a hand wheel, a valve stem, a valve cover, a valve body and a valve plate. The two ends of the valve body channel are the medium inlet and outlet respectively. Pass through the bonnet to connect with the valve plate, and the top is connected with the hand wheel. The bottom wall of the valve body channel under the valve plate is provided with a slightly convex arc surface, and the bottom surface of the valve plate is provided with a concave hole for inserting the slightly convex arc surface. , the height of the slightly convex arc surface is 2-6mm. The bottom walls of the medium inlet and outlet are provided with arc-shaped conical surfaces, the small openings of the arc-shaped conical surfaces face outward, and the inclination angle α is 3°-8°, preferably 5°. When the valve plate moves down and closes, the slightly convex arc surface will be inserted into the concave hole to establish the lower support point, coupled with the upper support of the valve stem, so that the original suspended valve plate becomes a structure with support up and down, completely solving the original The soft-sealed gate valve has technical problems that the valve plate is prone to displacement, damage, short service life and affecting the sealing effect due to the lack of support at the lower part of the valve plate.