The invention relates to a minimum available configuration detecting system and a method. The system includes a function detecting module, a state detecting module, a fault recording module, a computing module and a display module, wherein the computing module computes the minimum available configuration grade of computer information and a control system of a power station according to the available grade, and judges the availability of the computer information and the control system of the power station by comparing with the fault condition or according to the detecting result for the function availability of the function detecting module. By adopting the technical scheme, when the computer information and the control system of the power station are failed namely a computer workstation is partially failed, the invention can stay on the computer workstation to monitor the power station to the maximum degree according to the monitoring requirements for the working conditions of different power stations under the premise of ensuring safety of the power station, so as to prevent state recession of the power station due to that the computer workstation is given up for some time, thereby leading the running of the power station to be more economical.