A fluorescence optical-fiber spectrometer was developed based on fluorescence of imidacloprid insecticide for monitoring carbamate pesticides.The instrument makes use of xenon lamp as excitation light and combines with fiber-optical sensing and CCD technology to implement rapid determination of imidacloprid.And the same time,the instrument is also be applied to measure imidacloprid in river water and ground water.The recovery may be closed to 100%.