Nuclear powerturbinehigh pressure valve hydraulic control mechanism and driving system. In the first hydraulic passage of the nuclear powerturbinehigh pressure valve hydraulic control mechanism, the first end of the first emergency electromagnetic valve is connected with the oil supply device through an oil return passage, the second end is connected with the control oil chamber of the first pilotcartridge valve through a first throttle hole, and is also connected with the first end of the first check valve; the second end of the first check valve is connected with the pressure oil chamber of the first pilotcartridge valve, and is also connected with the first end of the first main cartridge valve; the second end of the first main cartridge valve is connected with the driving mechanism through a power passage; the first pilot cartridge valve and the first main cartridge valve are also connected with the oil supply device through oil return passages; in the case that the first emergency electromagnetic valve is closed by power-off, the first pilot cartridge valve and the first main cartridge valve are opened in turn, forming an oil path from the driving mechanism to the oil supply device. The nuclear powerturbinehigh pressure valve hydraulic control mechanism can eliminate the driving mechanism failure.