As a city with large population and food supply, Fuyang’s rapid urbanization process in recent decades has caused urgent attention to its climate and environmental issues. Research on the long-term boundary layer structure and its relationship with meteorological conditions in the context of climate change is of significant importance. By using conventional meteorological observation data from Fuyang, Anhui Province, high-resolution L-band sounding observations from Fuyang sounding station between 2010 and 2019, as well as the ERA5 reanalysis data, we employed the bulk Richardson number method to calculate the planetary boundary layer height (PBLH). The characteristics of the long-term PBLH variations in the Fuyang region were compared and analyzed. The relationships between PBLH and meteorological factors such as 10-m wind speed, near-surface temperature, relative humidity and surface pressure were analyzed at monthly, seasonal, and interannual scales using multi-year data. The discrepancies between the observed PBLH and those from the ERA5 were also examined. The results indicate that the PBLH observed at 08:00 and 20:00 throughout the year in Fuyang remained below 500 m. This was due to the relatively weak solar radiation during these time periods, leading to under-developed boundary layer or transitioning towards nocturnal stable boundary layer conditions. The PBLH at 20:00 was higher than at 08:00, which is attributed to the combined effects of lower pressure, higher temperature, and lower relative humidity in the evening, which led to a higher uplifting of the PBLH and surpassed the effect caused by lower wind speeds. The PBLH exhibited significant seasonal variations regardless of the observation time (8:00 or 20:00), with the order of seasons being summer > spring > winter > autumn. The ERA5-derived PBLH exhibited a generally consistent seasonal variation pattern with the observations. The ERA5 PBLH was 23 m higher than the observed PBLH at 08:00, primarily due to elevated wind speeds, higher temperatures, and lower atmospheric pressure in ERA5. However, at 20:00, the ERA5 PBLH was 99 m lower than the observed PBLH with more complex influencing factors. The multi-year monthly averaged correlation coefficients between ERA5 and observed PBLH were relatively high, with values of 0.91 and 0.74 at 08:00 and 20:00, respectively, indicating the potential of using ERA5 data for long-term trend studies of PBLH in Fuyang and southeastern regions. The fluctuation patterns of observed and ERA5 annual average PBLH showed overall consistency over the years, but there is stable in the data of observed PBLH, while in ERA5, a slightly decreasing trend is demonstrated (not statistically significant at p<0.05). At the monthly average scale, surface meteorological factors significantly influenced PBLH, with atmospheric pressure and wind speed exerting a greater impact compared to temperature and humidity. The multi-year monthly averaged PBLH from ERA5 exhibited a significant negative correlation with surface pressure and a strong positive correlation with surface wind speed. The correlation was stronger at 08:00 compared to 20:00; The relationship between the annual average PBLH value and the ground meteorological elements is not significant, therefore, although climate change leads to an increase in surface temperature and relative humidity, the change of annual average PBLH is statistically not significant. Intensive observations indicated that both observed and ERA5-derived PBLH gradually increased from 02:00 to 20:00, followed by a decrease, reflecting the typical diurnal variation characteristics of boundary layer height, with a deeper boundary layer during the day and a shallower boundary layer at night.