An arrangement method for in-phase high-voltage distribution devices includes the following steps that (a) the in-phase high-voltage distribution devices needing to be arranged are selected, and voltage classes are determined; (b) the maximum value Emax in electric field intensity E distribution of the area where the in-phase high-voltage distribution devices are located is determined; (c) the maximum value Emax in electric field intensity E distribution is made to be larger than or equal to air breakdown electric field intensity Ea, and therefore the positions of the two in-phase high-voltage distribution devices are determined. According to the arrangement method, the in-phase high-voltage distribution devices are arranged objectively, substation electrical primary design improvement work of the electric power department is guided scientifically, reliable bases are provided for arrangement design work of the in-phase high-voltage distribution devices, the floor space of a distribution device site is effectively reduced, the purposes of reducing damage to the surrounding environment, the engineering volume and engineering cost are achieved, and remarkable economic benefits and social benefits are obtained.