This study systematically investigates the failure mechanism and dynamic process of a long run-out landslide in Jichang town based on multiple-integrated geotechniques including field investigations, remote sensing analysis, electrical resistivity tomography (ERT) analysis, seismic signal analysis, and numerical simulations. Multi-period remote sensing images show that there was no deformation of the slope before failure that the landslide occurred suddenly, and that rainfall was the main triggering factor. The field investigations and the ERT analysis show that the bedrock of basalt below the Quaternary deposits is moderately strongly weathered and fractured and was full of water from the heavy rainfall that occurred before failure. In addition, field investigations and ERT results show that the geometry of the slip surface is stair-stepping, indicating that there was at least one locked segment on the potential failure path before failure. The authors conclude that the failure of the Jichang landslide was caused by fractured rock filled with rainwater that reduced the shear strength of the discontinuous planes and increased the pore water pressure and weight of the material; this caused the damage of the locked segments and triggered a sudden landslide. Seismic signal analysis shows that the entire run-out process lasted for 60 s and can be divided into three stages: the initial failure stage, the acceleration stage, and the deposition stage. The initial failure stage lasted for 20 s, the acceleration stage lasted for 15 s, and the deposition stage lasted for 25 s. The results of the landslide run-out simulation based on a 3D SPH model are consistent with the seismic signal analysis and show that the peak speed of the sliding mass reached up to 45 m/s. This study shows that the multiple-integrated geotechniques are very useful in run-out landslide investigation and can be used as a reference in similar future studies.