Loosening part monitoring and alarming system and method of nuclear power station

The invention discloses a loosening part monitoring and alarming system of a nuclear power station. The system comprises accelerometers, preamplifiers, signal conditioners, a data collection card and a data analysis and diagnosis computer in successive connection, each signal conditioner comprises an analog electronic switching circuit, a signal supervision unit, a signal monitoring unit, an addition circuit and an AC and DC signal separating circuit, the input end of the analog electronic switching circuit is connected with a controller interface, a photo coupler isolation circuit and a surge protection circuit, the input end of the surge protection circuit is connected with a current excitation circuit and a signal input interface, the signal output end of the AC and DC signal separating circuit and the input end of the addition circuit are successively connected with an AC signal conditioning circuit, a gain adjusting turn button and a gain conditioning circuit, and a DC signal conditioning circuit is connected between the signal output end of the AC and DC signal separating circuit and the signal input end of the addition circuit. The invention also discloses a loosening part monitoring and alarming method of the nuclear power station. The system and method of the invention can effectively reduce the probability of false alarm and omission of alarm.