Abstract: A method for the maintenance and calibration of Agilent DD2-500 MHz nuclear magnetic resonance (NMR) spectrometer is discussed. A good working condition of nuclear magnetic resonance spectrometer is the precondition to obtain a high quality spectrum. In order to make the instrument with the optimal sensitivity and resolution, the actual operation methods for the maintenance and calibration were introduced from the aspects of probe tuning, uniformity of magnetic field maintenance and 90 degree pulse width calibration. The work provides the high quality test report for teaching and scientific research, and effectively prolongs the service life of the instrument.