The monitoring of the vibration state of the coolant pump of the pressurized-water reactor (PWR) nuclear power units is one of the important tasks in the maintenance of the nuclear power plants. In this work, in view of the demands for the acceleration sensor with high temperature resistance and strong radiation resistance for the vibration state monitoring of the coolant pump of a nuclear power plant in our country, the working characteristics of piezoelectric acceleration sensor in extreme environments are studied. The experimental results show that the working temperature of the proposed sensor is up to -55~480 ℃, the radiation resistance is up to 1×106 Gy. The operating state of the sensor has been verified through the vibration bench test. The results show that the output vibration signals of the sensor are consistent with that of the 5g(g≈9.8 m/s2） and 10g standard vibration signals. A vibration monitoring scheme than meets the requirements of nuclear power field application is proposed, and has been applied to a coolant pump of a nuclear power plant in our country. The experimental results meet the needs of nuclear power plants and lay a technical foundation for future batch application.