The invention provides a water turbine spray pipe capable of achieving buffered closing of a needle tip. The water turbine spray pipe comprises a nozzle head, a cylinder sleeve, a piston, a liquid inlet channel, a liquid outlet channel and a needle rod, wherein the nozzle head is provided with a nozzle; the nozzle head is connected with a water supply pipe through a spray pipe body; the spray pipe body is connected with a cavity seat provided with hydraulic cavities through rib plates arranged at intervals; the cylinder sleeve and the piston are fixed in the hydraulic cavities; the liquid inlet channel and the liquid outlet channel communicate with the hydraulic cavity in the front end of the piston and the hydraulic cavity in the rear end of the piston correspondingly; and one end of the needle rod is fixed to the piston, and the other end of the needle rod penetrates through the cylinder sleeve and is connected with the needle tip. The water turbine spray pipe is characterized in that the opposite surfaces of the piston and the cylinder sleeve are provided with a groove and a flange correspondingly; a throttling hole is formed in the flange; the outer main hydraulic cavity and the inner auxiliary hydraulic cavity are formed after the flange and the groove are connected in a matched mode; and the main hydraulic cavity communicates with the auxiliary hydraulic cavity through the throttling hole in the flange. The closing process of the needle tip is divided into a fast closing stage and a slow closing stage, so that the motion impact force and water hammer force of the needle tip are effectively reduced, safe operation of a machine set is guaranteed, and the service life of the spray pipe is prolonged.