High-pressure large-diameter hydrogenation stop valve

The invention discloses a high-pressure large-diameter hydrogenation stop valve comprising a valve body, and a connecting piece is installed in the valve body; and a sealing block is arranged at the bottom of a sealing plate and matched with rotation of a clamping block and clamping of a clamping groove, the clamping block and the clamping groove are connected in a clamped mode to apply pressure to a sealing ring, the sealing ring automatically rebounds to fix the sealing plate, when a user replaces a valve clack, the clamping block and the clamping groove are separated, and the valve clack can be pulled out. The use cost is reduced while the convenience is improved, a bearing rotationally connected with the surface of a valve rod in a sleeving mode is arranged in a connecting block, a telescopic rod is matched to linearly guide the valve clack, so that the valve rod cannot drive the valve clack to synchronously rotate when rotating, the phenomenon that the valve clack rubs against a sealing seat is avoided,