Objective：To study the characteristics and correlative factors of pulse oxygen saturation（SpO₂）and exercise tolerance during the 6-min walk test（6MWT）in the stable chronic obstructive pulmonary disease（COPD）patients，aiming to provide a simple and effective objective assessment method for COPD patients. Methods：A total of 58 stable COPD patients and 21 control subjects were enrolled. General data，modified Medical Research Council dyspnoea scale（mMRC）score，COPD assessment test（CAT）score， pulmonary function parameters（such as FEV₁%Pred，FVC%Pred，D_LCO%Pred，D_LCO/V_A%Pred），and 6MWT-related parameters were collected. The study analyzed the differences in SpO₂ and exercise tolerance indicators between groups，and their correlation with commonly used COPD assessment indicators. Results：COPD patients exhibited a decline in exercise SpO₂ during the 6MWT， characterized by the occurrence of exercise-induced desaturation（EID），a decline in minimum SpO₂（SpO_2min）and mean SpO₂（SpO_2mean）， an increase in the percentage of time with SpO₂ below 88%，90%，and 92%（T₈₈，T₉₀，T₉₂）and desaturation area（DA）. There were differences in the 6 - minute walk distance（6 MWD）as a percentage of the predicted value（6MWD% Pred）and the desaturation distance ratio（DDR）between the two groups. SpO_2mean，DA，DDR and 6MWD%Pred were correlated with mMRC scores，FEV₁%Pred， FVC%Pred，and resting SpO₂（SpO_2rest）. DDR was also correlated with D_LCO%Pred and D_LCO/V_A%Pred. However，multivariable linear regression analysis showed that only mMRC scores，D_LCO%Pred，and SpO₂rest were independently associated with DDR. Conclusion： Continuous SpO₂ monitoring during the 6MWT，with parameters such as SpO_2mean，DA，DDR，and 6MWD%Pred，can effectively reflect pulmonary function and symptoms of stable COPD patients，suggesting its efficacy in assessment and management of COPD patients.