In order to solve the problem of the DVOR sideband and sub carrier in Chizhou Jiuhuashan Airport, Firstly, to eliminate the public part fault conditions of the system in accordance with equipment principle and trouble phenomenon; Secondly, to measure the signal using vector voltmeter and to eliminate the fault of the Subcarrier notch; Finally, to test the pathway between SMA assemblies and sideband antenna and found a cable head of SMA to SCU section contact is not good, the system return to normal after the replacement and installation of a new cable head. Through the analysis and processing of this case, a detailed ideas and steps are provided for DVOR trouble shooting.