Cut-off valve

The utility model provides a cut-off valve which comprises a valve body with a flow passage, a valve cap connected with the valve body, a valve rod extending to the inside of the valve body after passing through the valve cap and capable of moving up and down, a valve clack connected with the valve rod, and flanges connected on the two sides of the valve body, wherein the flow passage comprises an inflow passage, an outflow passage and a working passage arranged between the inflow passage and the outflow passage and matched with the valve clack, the valve body and the flanges are integrally cast-molded, and the cross section of the entrance of the outflow passage is elliptic. Since the valve body and the flanges are integrally cast-molded, the cut-off valve has the advantages of good overall structure, simple fabrication, low cost and long service life. Besides, the cross section of the entrance of the outflow passage is elliptic, so that the cut-off valve has a big flow rate.