Piston cooling nozzle, comprising a fuel injection pipe, fuel injection pipe is fixed in the metal ring on one side and a metal ring connected, bolt is provided with an oil inlet passage, the spool placed in the bolt, the spring pushes against the valve core and limit block props up the spring. The bolt is sheathed in the metal ring, metal ring into the oil hole and the bolt in the oil holes are aligned. Bolts into the oil channel and the cylinder block of an engine main oil channel is communicated, when the engine output power is larger, into the oil passage of the oil pressure increases, the pressure acting on the spool is increased, thereby compressing the spring, spool movement. At this time, the oil from the oil inlet hole to oil hole, ejected from the injection tube, the piston cooling nozzle. The structure is reasonable, and the acting force acting on the piston cooling nozzle is uniform.