The invention discloses a method for obtaining potential distribution of a 1,000kV metal oxide arrester. The method comprises the steps of (1) simulating potential distribution of the metal oxide arrester in normal running: (1-1) building a three-dimensional mathematic model of the potential distribution of the metal oxide arrester; (1-2) assigning a relative dielectric constant epsilon according to material attributes of components of the metal oxide arrester; (1-3) applying a forced potential boundary condition; and (2) solving the three-dimensional mathematic model according to the assigned relative dielectric constant epsilon and the forced potential boundary condition so as to obtain potential distribution when resistors in different positions cause a short circuit or are damped. According to the method, the complete three-dimensional model of the 1,000kV zinc oxide arrester is built; the peripheral space of the arrester is simulated by using a finite large air domain; and the potential of a suspended conductor is processed by utilizing a freedom coupling function in ANSYS, so that the potential distribution of the arrester is accurately calculated while the calculation scale is reduced.