Abstract: Studying the variation of soil infiltration is helpful to analyze the mechanism of soil water movement in farmland. At the same time, soil infiltration characteristics affect the surface irrigation process, which is an important basis for the design of ground irrigation system. Based on the field test data, this study simulated and analyzed the soil infiltration process with three soil infiltration models（Kostiakov-Lewis model, Philip model and Horton model）. The infiltration uncertainty caused by spatial variation of farmland soil in infiltration process was investigated by adopting two random simulation methods（direct method, parameter mean method）of infiltration. The evaluated indicators were the interval size and its stability of cumulative infiltration amount changed with 95% confidence. The effects of different random simulations methods and three models in the infiltration process were compared and analyzed. Finally, the model and stochastic simulation method suitable for the infiltration characteristics of the farmland were determined. The results showed that the correlation coefficients of the three models in the field experiment were all above 0.98, and there was no significant difference in fitting accuracy. In terms of the degree of spatial uncertainty（determined by root-mean-square error）：direct method>parameter mean method, in which the combination of the Kostiakov-Lewis model and the parameter mean method had less uncertainty, and the combined simulation effect was better. It is more suitable for the simulation of soil infiltration at farmland scale.

Key words: soil infiltration, stochastic simulation, root mean square error, uncertainty