The angle-type sludge valve is a valve used in water supply systems where fire-fighting water and domestic water are connected in parallel, to adjust the direction of water supply. When there is an urgent need for a large amount of water for fire-fighting, domestic water can be immediately cut off to ensure sufficient fire-fighting water; when the pressure for fire-fighting water decreases, the valve will automatically open, remaining in a normally open state, and resume domestic water supply. There is no need to set up a dedicated fire-fighting water supply network, saving construction costs and water usage. The sludge valve has high control sensitivity, is safe and reliable, easy to debug, and has a long service life