Geological disaster causes loss of lives and damage to man-made and natural stuctures. In this paper, a coupling method with optimal combination weighing law and extension model was established. Based on dynamic impact factors such as forest coverage, annual average rainfall, topography and gemorphogy, geologic structure, and type of rock and soil, the amount of disaster points and human engineering activities, we chose Jilin Province in China as the case study area. We made a spatial analysis and drew a geological disaster susceptibility zonation map using GIS technology. In addition, we established a geological disaster forecast and early-warning model. The results are as follows: 1) the couple method is an innovative and significant exploration, 2) geological disaster susceptibility zones in Jilin Province were divided into four areas, and 3) the forecasting and early warning model has a relatively high accuracy of forecast and early warning.