To address the issue where traditional and existing optical path suppression schemes perform well at room temperature but struggle to maintain performance across all temperature ranges, a relative intensity noise （RIN） suppression scheme based on dual detectors is proposed. This scheme uses dual detectors to separately detect optical signals passing through different paths and subtracts these signals in the circuit after synchronization to eliminate RIN, thereby improving the precision of fiber optic gyroscope. Additionally, the impact of different modulation depths on gyroscope output and potential improvements to the scheme are explored. The experimental results show that with a modulation depth of 3π/4 and the use of RIN suppression measures employing dual detectors, the scheme effectively enhances the precision of fiber optic gyroscope and meets usage requirements across all temperatures.