Abstract: Based on the methane flux observation data of Longbao Wetland in the source area of the three rivers from April to September 2021, the dynamic changes of methane flux in the alpine wetland of the source area of the three rivers and the impact of environmental factors on the methane flux were analyzed. The vorticity observation instruments included the CSAT3A ultrasonic anemometer and Li 7 700 open circuit infrared gas analyzer. These instruments were installed at a height of 2 meters and operated at a frequency of 10 Hz. The software of Eddypro 7.0.6 was employed to calculate the primary methane flux data. Data points with a quality level of 2, recorded during precipitation periods, and obtained during nighttime with a friction wind speed (U*) below 0.15 m/s, were excluded from the analysis. Consequently, secondary methane flux data was obtained by applying these criteria. In order to identify and remove outliers in the secondary data, the Laida criterion was utilized to eliminate data points with magnitudes ranging from 101 to 102. Following the quality control procedures, a total of 3 839 valid methane flux data points were obtained for the Longbao Wetland site. Methane emissions in the Longbao wetland predominantly occurred during the growing season, with methane flux ranging from 10^-2 to 10^-3 μmol · m^-2 · s^-1. The maximum daily and monthly emissions occurred in August, reaching a peak of 92.7 mg · m^-2 · d^-1 and 1 870 mg · m^-2 · mon^-1, respectively. The Longbao Wetland demonstrated a differential methane flux pattern, with lower fluxes associated with the Flux-Source Area located on the north side, and higher fluxes observed on the south side. The maximum flux was four times greater than the minimum flux. The Flux-Source Area had a significant impact on the results of attribution analysis. By measuring the average methane flux at an interval of 0.1 Hpa in saturated water vapor pressure and an interval of 1 °C in temperature, a fitting model was established to relate these variables to the methane flux in the two contributing source regions. It was worth noting that the determination coefficients and parameters of the model exhibited considerable differences when the contributing source regions were altered. For alpine wetlands ecosystems, the Flux-Source Area was also a factor that needed to be incorporated in the relationship between environmental factors and methane flux.