Abstract: In order to analyze and clarify some key issues in the field of sudden geo-hazard risk assessment, on the basis of general analysis of purposes, basic principles, structure and core contents of the technical guideline for geo-hazard risk assessment, this paper has focused on the working process of risk, probability and possible consequence assessment. Six basic principles, structure and core contents which should be followed are put forward; qualitative analysis with combination of quantitative evaluation method and techniques are achieved with emphasis on practical techniques and GIS application; basic working process of risk, probability and possible consequence geo-hazard assessment are put forward. Lastly, there are some brief discussions on some of the major difficulties which are easy to be confused in terms of geo-hazard risk assessment, which can be referred to for the technical guideline revision and improvement.