In order to calculate the intensity distribution of ring resonators, a numerical model is obtained with Collins’ formula and finite element propagation matrix method. The intensity distribution of planar resonator is unsymmetrical due to astigmatism. The axis mode has an elliptic facula, but high order mode can be detached. When increasing the coordinate rotation angle in the nonplanar ring resonator, components in the tangential plane and sagittal plane are coupled. The intensity distribution of high order modes changes with the coordinate rotation angle which shows the influence of coordinate rotation angle on the field modes. The intensity distribution of ring resonator with 90° rotation is nearly axis-symmetrical, but it is different from that in the linear resonator.