The invention relates to the technical field of electric metering, and provides a substation metering gate abnormity fast judgment and alarm method. The method comprises the steps that 1 power data in a collecting system database are extracted; 2 a bus power balance, line loss and transformer loss automatic calculation template is made; 3 the metering gate power data of a target line are calculated; 4 whether a metering gate is abnormal is determined; 5 an alarm is timely given to an administrator; and 6 on-site inspection staff eliminate the shortcoming in time. According to the invention, a power report procedure system is used to carry out daily monitoring on the substation metering gate of the whole grid; an abnormal metering gate is timely found and analyzed to give out an alarm in advance, which is advantageous for maintenance personnel to carry out maintenance in time to accurately eliminate the shortcoming; and the power collecting system of a power supply company can collect accurate power data.