Making full use of the graphical user interface of the L band radar soft panel can realize the monitoring, adjusting, and controlling of radar and provide technical parameters for the maintenance of radar. The components and characteristics of the L band radar soft panel are introduced, and the virtual measuring instrument, virtual switches and buttons, and the functions of each component in the real time detecting information window are analyzed. Based on information provided by the soft panel (normal state, fault phenomenon), failure causes and faulted parts are discussed.Practice has proved that radar parameters, performance parameters, and real time data provided by the soft panel are irreplaceable in the operation, maintenance, calibration, and overhaul of radar.