In order to study the deviation of low-level temperature in squall line simulated by WRF (Weather Research and Forecasting) model, a squall line case in North Jiangsu Province on June 14, 2009 was selected for analysis.The simulation results show that the WRF has defects in simulating the diurnal variation of low-level temperature, which mainly show that the simulated daily maximum temperature lags behind the observation for 2-3 h, and the cooling range of simulated low-level temperature in the evening is 2-3℃ lower than the observation.Comparative experiments show that by changing the parameterization scheme of the boundary layer, the temperature exchange between the boundary layer and the free atmosphere is weakened, and then the simulation results are improved to a certain extent, that is, the simulated squall line intensity and low-level temperature are more similar to the observations.Without changing the boundary layer scheme, by adding the ground automatic encryption observation station data into the simulation, it can also improve the simulation results.