Abstract: Based on long term surface displacement monitoring data of loess floor dump slope which has been affected by underground mining, we analyze and summarize the influence factors of displacement firstly, and then quantify the effect of each factor on the slope deformation. According to the factors, we disassemble three influencing factors of loess floor creep, underground mining and rainfall from the total displacement. Slope deformation statistical model is established by using the disassembled results. Finally, the model is used to analyze Yinwan dump slope surface displacement monitoring data. We use the established model to analyze a set of typical data to determine the influence of various factors on the slope deformation and their basic characteristics. Results show that the model can be a good description of slope deformation and failure; the theoretical analysis result coincides with the actual result and has the value of engineering application.