The invention relates to the technical field of water turbines, in particular to an adjusting device for high-pressure oil outside of water turbine blades. The adjusting device comprises a rotating wheel body, an oil distributor and a servomotor; the servomotor is located outside the rotating wheel body, a piston is slidably connected in the servomotor, the piston is connected with a piston rod, the piston rod is movably connected inside the oil distributor, and an oil collecting tank is arranged on the joint of the piston rod and the oil distributor in a sleeving mode; a sealing part is arranged on the position, between the bottom of the oil collecting tank and the piston rod, of the piston rod, an oil guide cylinder is arranged in the oil collecting tank, the oil guide cylinder is arranged on the piston rod in a sleeving mode, an oil discharge pipe is arranged on the oil collection tank, and the oil discharge pipe is connected with an oil return tank. According to the scheme, the problem of oil leakage of the oil distributor is solved, high-pressure oil is collected into the oil collecting tank, the oil is discharged into the oil return tank from the oil discharge pipe of the oilcollecting tank, and collection and utilization of the oil are realized.