Solar array is the important part of the satellite’s Electrical Power Supply, the failure of the solar array may lead to the loss of some or all of the satellite’s functions, so fault location in time and solution strategy of solar array is particularly important. The thesis studied the on-orbit failure of GEO satellite’s solar array, analyzed the fault location according to the related telemetry, and researched the solution of all kind of the faults. The thesis contributes to the satellite control center to locate faults in time and the satellite manufacture to improve the design of the solar array, it is helpful to improve the reliability and safety of the satellite’s on-orbit running.