The invention provides a geophysical method and device for landslide hydrologic condition monitoring, and belongs to the field of geological disaster monitoring. The device comprises a landslide surface potential monitoring device, a landslide drilling potential monitoring device, a control and measurement terminal, a geoelectric field power supply control power source, a long electrode and a short electrode thereof. The long electrode sequentially penetrates a sliding body, a sliding zone and a sliding bed, and meanwhile the short electrode is arranged close to the earth surface long electrode. A geoelectric field power supply device is used to apply artificial electric fields for the long electrode and the short electrode. If hydrogeological condition changes of a weak zone, a weak intercalated layer, a weak argillation zone, and a shear movement structural surface of a landslide cause abnormality of an electric field, potential changes would be observed through the surface potentialmonitoring device and the landslide drilling potential monitoring device, so as to realize predict landslide deformation and a critical sliding state, and perform landslide hazard warning. Thus, occurrence of landslide geological disasters is effectively prevented. The method and the device has characteristics of low cost, simple implementation and continuous monitoring of 7x24 hours.