Abstract: In order to predict the omnidirectional propagation characteristics of radar waves over the sea surface, a radio wave propagation model based on cylindrical coordinate parabolic equation is proposed and used to study the coverage range of marine radar. In this paper, the forward parabolic equation in cylindrical coordinate system is derived from Helmholtz equation. By using the orthogonality of trigonometric functions in the general solution of the parabolic equation, the excitation coefficients of each wave propagation modes are solved, and the stepwise iterative algorithm of the cylindrical coordinate parabolic equation is realized by combining the split step Fourier method, to predict the propagation characteristics of the radio waves in space. Numerical examples show that the method proposed in this paper can overcome the azimuth limitation of the traditional three-dimensional cartesian coordinate parabolic equation method, which propagates about 30° along the axis, and realizes the omnidirectional calculation. Compared with quasi-three dimensional parabolic equation, it has higher calculation accuracy. Based on the proposed method, the influences of atmospheric waveguide and rough sea surface on radar detection performance are studied, the simulation results have important significance for constructing digital battlefield at sea.