The retrieval method for ozone (O₃) profiles was investigated using spectra measured by the Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) technique in Kunming and Shanghai. Through simulations,it was found that stratospheric O₃ differential slant column density (DSCDₛₜᵣₐ) significantly affects tropospheric O₃ differential slant column density (DSCDₜᵣₒₚ). The Umkehr effect was integrated into MAX-DOAS, and O₃ DSCDₛₜᵣₐ calculated from O₃ profiles above 10 km—was used to separate O₃ DSCDₜᵣₒₚ from total O₃ DSCD (DSCDₜₒₜₐₗ). Subsequently,Differential Optical Absorption Spectroscopy (DOAS) technique and the optimal estimation method (OEM) were combined to retrieve tropospheric O₃ profiles. Using Electronic Chemistry Cell (ECC) O₃ sounding profiles in Kunming as a reference, comparisons between MAX-DOAS (Umkehr) profiles and verification profiles from the Ozone Monitoring Instrument (OMI),Dobson spectrophotometers, and Brewer spectrophotometers showed good consistency, with deviations only at specific heights.Near the tropopause, the relative deviation between MAX-DOAS retrievals and ECC data increased;however,MAX-DOAS retrievals at heights of 20–40 km were highly sensitive to the Umkehr effect and exhibited small deviations from ECC data. For tropospheric O₃ profiles retrieved via MAX-DOAS (OEM),the maximum relative deviation between O₃ concentrations in the 1-km surface layer and ECC data was-7.8 %.Additionally, O₃ profiles retrieved by the Shanghai MAX-DOAS (Umkehr) were consistent with OMI profiles. Overall,combining the DOAS technique with the Umkehr principle enables the retrieval of stable and reliable O₃ profiles.