The invention belongs to the technical field of valves, and discloses a self-sealing anti-leakage valve which comprises a valve body and a connecting
assembly. A buffer
assembly; an adjusting
assembly; a cleaning assembly and a
cut-off assembly. According to the invention, by installing the
cut-off assembly for auxiliary movement, when a
piston block reaches a gap of a partition plate and continuously moves downwards, the
piston block encounters the pressure of
water flow in a right cavity to form a
water hammer effect, and at the moment, three
metal rods contact a groove ring and move downwards
clockwise in a groove; the L-shaped rod can be pushed out under
clockwise pushing of the cross plate and the oval groove, the shape of the L-shaped rod is a section
conical surface, when the L-shaped rod continuously stretches out to be close to the bottom face of the partition plate, additional downward extension force can be provided for the
piston block, the piston block can be assisted to be completely attached to and close a gap in the partition plate, and therefore the sealing effect is good. The problem that in the gradual closing process of an opening and closing piece of the valve,
water flow can generate certain
impact force on the opening and closing piece, and the
water hammer phenomenon is generated to cause leakage is solved.