The existing conformal transformation is based on the calculation of two-dimensional space

but the feasibility and mapping rule of conformal transformation in three-dimensional space are not studied.In view of this problem

the applicability of conformal transformation in three-dimensional space is studied in this paper and the corresponding relationship between conformal transformation function of terrain boundary and actual terrain parameters is given.The conformal transformation formula of symmetrical mountain shape is studied and the spatial electric field of terrain boundary is simulated by using finite element software and conformal transformation analytic method respectively.It is shown by the result that the relative error of calculation result of both methods is less than 0.1% and the conformal transformation algorithm of two-dimensional symmetric terrain can be extended to the model of three-dimensional rotational terrain.According to the results obtained by the study and calculation in this paper

the corresponding conformal transformation function can be obtained regularly in accordance with the actually measured mountain shape parameters

or the conformal transformation parameters is changed to match with the actual mountain shape.The actual terrain boundary is transformed into simple terrain boundary so to solve the corresponding electromagnetic problems.