The invention discloses a method of eliminating single point abnormal data from a merging unit. The method comprises steps: an actual sampling value of a certain sampling point which is about to be sent by the merging unit is acquired; an ideal sampling value corresponding to the actual sampling value is calculated; mutation characteristics of the actual sampling value which is about to be sent by the merging unit are judged; the calculated ideal sampling value is used for replacing the actual sampling value and is sent; and the actual sampling value of the current sampling point is sent. The method of eliminating single point abnormal data from the merging unit disclosed by the invention has the beneficial effects that through comparing original sampling point data before and after the sampling point, the single point abnormal data can be effectively eliminated, the sensitivity is controlled according to the size of a threshold, load fluctuation can be effectively avoided, the method can be used for current and voltage single point abnormal data elimination, the performance of the merging unit can be improved at a source end, protection at a rear end and the processing algorithm of a measurement and control device are simplified, the system operation level can be effectively improved, and the device reliability is improved.