Abstract: The vulnerability assessment model of water-inrush from coal floor based on the variable weight theory can solve the problem that the constant weight can’t reflect the effect on the evaluation result caused by the inner differ- ence of water inrush control factor index value. But there is no uniform analysis and determination method of interval threshold and adjusted weight parameters in the variable weight assessment model of water-inrush from coal floor,that determines which weights of water inrush controlling factors will be adjusted and their amplitude of adjustment. Ac- cording to the spatial distribution differences as well as some similar features of each controlling factors index value in water-inrush from coal floor,this paper uses the cluster analysis method to determine the interval threshold of each var- iable weight controlling factor. At the same time,it also tries to propose a feasible method that can satisfy decision- maker’s preference to determine the adjusted weight parameters in the variable weight evaluation model. On the basis of the above work,taking Xinglongzhuang Coal Mine in Shandong province as an example,the solution is illustrated and the result is verified.