In recent 20 years, fibre laser system has been developed rapidly and widely used for its high quality, high efficiency, high robustness, and compactness. However, there are still many factors (such as non-linear effect, thermal effect, and mode instability) that limit the further increase of power of fibre laser system. Stimulated Raman scattering (SRS) is one of the main limitations in the transmission process of fibre lasers. It not only reduces the output efficiency of fibre lasers, but also increases the damage risk of reverse Stokes light to the system. Recent studies have shown that SRS in low-mode fibres can lead to quasi-static mode degradation in addition to mode instability. With the introduction of multi-sensor enhancement technology in the fibre field, it becomes an effective means to popularise high-power and high-beam quality fibre lasers. Based on the multi-sensor signal enhancement technology, this paper explores the influence of this technology on the output efficiency of SRS in the mode-reducing fibre laser, which provides a new idea and method for the output efficiency and transmission analysis method of fibre laser.