The utility model discloses a waterpower oscillator belongs to drilling machinery technical field. Waterpower oscillator includes: the vibration assembly, valve assembly and the motor assembly that communicate in proper order, vibration assembly include first casing, vibration axle and spring, and vibration axle slidable ground cartridge is equipped with first draw -in groove on the periphery wall of vibration axle in the upper end of first casing, be equipped with the second draw -in groove on the internal perisporium of first casing, and the spring card is established between first draw -in groove and second draw -in groove, the valve assembly includes second casing, first valve block, second valve block, second casing and first casing intercommunication, first valve block off -centre in second valve block and mutual intercommunication, the motor assembly includes third casing and rotor, and rotationally the cartridge is in the third casing and in the second casing for the rotor, and first valve block coaxial arrangement serves at the lower of rotor, and first valve block passes through the clearance intercommunication between runner and rotor and the second casing. The utility model discloses can reduce the coefficient of friction between the drilling tool and the wall of a well.