The invention relates to a load and single phase ground fault identification method based on the voltage plane. The method includes the following steps that a phase offset voltage (please see the formula in the specifications) in the relay location and a positive sequence offset voltage (please see the formula in the specifications) with the phi phase as reference in the relay location are determined; the movement track of the phase offset voltage (please see the formula in the specifications) in the relay location and the movement track of the positive sequence offset voltage (please see the formula in the specifications) with the phi phase as reference in the relay location are determined; by comparing the phase position of the movement track of the phase offset voltage (please see the formula in the specifications) in the relay location with the phase position of the movement track of the positive sequence offset voltage (please see the formula in the specifications) with the phi phase as reference in the relay location, whether faults exist or not is judged. With the method, the motion performance of an existing electric transmission line can be improved when distance protection is under overload, and the method has great significance in stable and safe operation of a power grid and limitation on range extension of accidents.