Aiming at the problems existing in the maintenance of observation equipment, by use of the NI PXI virtual instrument technology, and the LabVIEW graphical programming software platform, an automatic meteorological station fault diagnosis, testing, and maintenance system is designed based on the virtual instrument technology, mainly including the hardware design of the testing system, application software design, and dynamic maintenance database design, which realizes the functions of automatic meteorological station data acquisition, processing, analysis, diagnosis, file display, printing, etc. Through the test signal treatment by software programming to strengthen the function of adaptive test, using database retrieval function, the system realizes the fault similarity search function and improves the efficiency of fault testing and diagnosis.