A novel compound two-ring combined Rayleigh backscattering fiber optic rotation sensor (RBFORS) is demonstrated and simulated based on the working principle given by A. Kung. The theoretical model of the two-ring resonators combined RBFORS is established by using two 2×2 fiber star couplers. The output signal characteristics of optical time domain reflectometer (OTDR) are deduced and analyzed by optimizing the structure parameters of the two rings cavity lengths and coupling ratios. The experiment system is constructed by the two-ring with the lengthes of L1=1500 m and L2=1078 m and fiber couplers with the coupling ratios of k1=95.23% and k2=94.88%, respectively. The Rayleigh backscattering signals are measured at different rotation rates. The experimental results are agreement with the theoretical prediction. The measurement intensity is increased by utilizing the compound two-ring structure. Therefore, the valid data number is increased, which is helpful to identify and enhance the precision of the measurement rotation rate.