Orthogonal design was adopted to analyze the sensitivity of influencing factors of slope stability in this paper. Based on the analysis of environmental engineering geology of the slope, the main influencing factors and their value ranges were determined. Then appropriate orthogonal table was selected to determine the calculating scheme. Calculating method of slope stability was used to calculate the slope stability. According to the variance analysis of calculation results of influencing factors, significant degree and sensitive degree of each influence factor was determined. Taken Xirangpo, the bedding bank rock slope in new-built area of Badong in the Three Gorges reservoir area as an example, multi-factor sensitivity analysis was carried out based on orthogonal design, including the five important influencing factors, the volume weight γ, cohesion c of potential sliding zone, internal friction angle φ, earthquake acceleration a_h and the reservoir level H. Results show that sensitive degree of each influencing factor of the four layers of sliding zones is different. However, earthquake acceleration and internal friction angle are always the main influencing factors of the slope stability.