Ring resonator is a key unit of integrated optical waveguide gyroscope. Generally the Finite Difference Time Domain (FDTD) method is used to analyze the microscopic ring resonator, but this method can not be used to deal with the ring resonator in optical waveguide gyroscope, because the size of the model is too large (the radius of ring resonator is 10 mm). In this paper, an accurate method was demonstrated to design the ring resonator, in which the model was analyzed by together with the Beam Propagation Method (BPM), guided-wave optics and the theory of multiple-beam interference. In this method, the ring resonator was divided into two parts, the coupler and the bend waveguide, and the phase condition of optimum resonance was updated, the phase shift caused by the length of bend waveguide was added upon the propagation phase shift of the coupler. Parameters such as insertion loss y; coupler coefficient k; phase shift of the coupler; the propagation constant β, and the bending radiation loss of bend waveguide were obtained accurately by this method. Through the vector analysis, the intensity of resonance of the ring resonator was calculated, and the characteristics of ring resonator were shown. At the end of this paper, the optimization fabrication of optical waveguide resonator was discussed.