In view of the current situation that the optical coherence tomography (OCT) scanner has poor stability in clinical use, is easy to cause signal attenuation, and has short maintenance cycle, this paper collects clinical signal attenuation fault information by sampling from the mainstream 4-generation frequency-domain optical coherence tomography equipment in the market. Combining with the principle of OCT, we analyze the influence of internal components of OCT on stability by statistical principle, and the weight of each influence factor on the stability of OCT through analytic hierarchy process (AHP). According to the analysis results, the main factor affecting the long-term stability of OCT is that the spectrometer is locally heated to cause mechanical deformation, which leads to signal attenuation. At last, according to the analytic hierarchy process, we briefly discuss the methods to improve the long-term stability of OCT.