The present invention provides a mobile communication network management system and a base station single board diagnosing method. The method comprises the following procedure: Step A: the network management system puts the single board diagnosis request transmitted to the main controlling board of the base station in the serial scheduling controlling queue in sequence; Step B: the network management system transmits the single board diagnosis request at the first position of the serial scheduling controlling queue to the main controlling board of the base station. Step C: to wait for the return result of the main controlling board of the base station and the time of the preset diagnosis overtime controlling time, the sequence of the residual requests in the serial scheduling controlling queue is moved upward, to return back to Step B. The present invention can release the processing pressure of the main control board of the base station, and improve the diagnosis efficiency and the diagnosis success ratio of the single board existing dependence relationship in the base station equipments.