Using an improved inexion point method (IIPM), we investigate atmosphere boundary layer (ABL) height evolution over Hefei during the total solar eclipse on July 22, 2009. A lidar ceilometer is used in ground-based observations. Estimations of ABL heights before, during, and after the solar eclipse are analyzed using the IIPM. Results indicate that the IIPM, which is less sensitive to background noise, is more suitable in detecting ABL height and temporal evolution. Data demonstrate that the total solar eclipse resultes in a decrease in ABL height, indicating a suppression of turbulence activity, similar to that observed during the sunset hours. Changes in ABL height are associated with a slow change in temperature, indicating a significant weakening of penetrative convection and a time lag between ABL response and the reduction in solar radiation.