The construction site of the freezing reinforcement method for the connecting channel in sand layer with rich water of one section in Zhengzhou section from Zhengzhou airport to Xuchang city was taken as an engineering example, the temperature field and seepage field control equations of fluid thermal coupling theory were adopted, a two-dimensional numerical calculation model for the cross-section of the connection channel with 2.0 m depth was constructed with COMSOL software, the fitting measured temperature curve of the salt water circuit was built with Logistic function, the fitted equation was used as an interpolation function to define the temperature of the freezing tube, temperature field nephogram and temperature curve during the freezing process of connecting channel were obtained through numerical calculation, the accuracy and rationality of the numerical model were verified by comparing the numerical results with on-site measured data, and the influences of the factors of groundwater flow rate, freezing tube spacing, freezing tube diameter, and initial ground temperature on the temperature field development were further studied. The single factor sensitivity analysis method is introduced, the sensitivity of each factor on the freezing wall intersection time was solved, the magnitude order of the influence of various factors was determined, the sensitivities were compared and it was found that: to reduced the spacing between freezing pipes is the best choice to weaken the influence of groundwater flow rate on the freezing temperature field when the groundwater flow rate is high; to increase the diameter of the freezing tube or reduce the spacing between the freezing tubes can improve the freezing efficiency when the initial ground temperature is high.