The principle of Kerr noise is analyzed in the integrated optical resonator gyroscope (IORG), and the mathematical model is built by the theory of guided-wave optics, the relation of the fundamental detection limit caused by the Kerr noise Ωk is formulated. Furthermore, the curve of resonator length with Ωk under different spectrum line widths of laser is simulated. As to the prominent reason of Kerr noise in the IORG which is the unbalance splitting ratio of integrated optical modulation, the calculation and software simulation are carried out. After that, the suppression methods to eliminate the Kerr noise are put forward. Finally, the experimental setup is built up and by adjusting the adjustable attenuator the equal optical intensity is realized, which shows that the Kerr noise in the IORG is effectively suppressed simultaneously.