Nuclear power plant boron concentration on-line monitoring device and method

The invention discloses an on-line monitoring device and method for the boron concentration of a nuclear power plant. The on-line monitoring device comprises a vibration sensor, wherein the vibration sensor comprises a vibration tube through which measured liquid flows, and a vibration excitation element and a vibration pickup element which act on the vibration tube; the main control module is configured to output a driving signal to control the excitation element to provide excitation force for the vibration tube, so that the vibration tube and the liquid to be detected generate resonance, a vibration pick-up signal of the vibration tube collected by the vibration pick-up element is obtained, an optimal vibration frequency band is obtained from the vibration pick-up signal, and multi-parameter matrix conversion is performed on the optimal vibration frequency band to identify concentration distribution; and the concentration of the measured liquid is obtained according to the frequency-concentration distribut