Abstract: This study takes the high slope of Maiwan Water ConserVancy Hub in Tunchang County, Hainan Province as the research object, for the unsaturated seepage intrinsic model parameter identification difficulties, with the help of wireless transmitter, data acquisition instrument and other monitoring devices, carry out on-site slope infiltration experiments, obtain monitoring data combined with the differential evolution method on the parameters of the Van Genuchten model (\alpha , n, \theta _\texts, \theta _\textr, K_\texts) for the global inversion. Through PLAXIS software to establish a finite element model for numerical simulation, analyze the pattern of change of the simulated values and compare with the measured values to verify the reliability of the parameters obtained from the inversion. The results show that the numerical simulation results driven by the inversion parameters are highly consistent with the measured data, and the error at each depth is within 5%. The accuracy of the numerical simulation is verified through experiments, which provides a parameter basis for the study of unsaturated seepage on slopes in tropical regions and a reference for the identification of unsaturated hydraulic parameters of this type of soil.