Abstract: Monitoring, analyzing, and measuring the real-time change of radio frequency (RF) signal plays a key role in optimizing signal spectrum efficiency. Real-time spectrum analyzers use digital fluorescence analysis technology to observe, measure and analyze time-varying signals, which have become an important means to monitor transient signals. In this paper, the key technical principle of the real-time spectrum analyzer is introduced, and the calibration methods for real-time bandwidth analysis and full-capture minimum pulse width-amplitude ratio are studied and proposed. According to the main functional characteristics of the real-time spectrum analyzer, the calibration methods of real-time bandwidth analysis and full-capture minimum pulse width-amplitude ratio are experimentally verified, and the uncertainty analysis and evaluation are carried out.