Abstract: The stability of filling pipeline is the key to keep safe operation for the filling system，while filling pipeline blockage is the most frequent accident in slurry delivery process.In order to rationally analyze the direct and indirect causes for the filling pipeline blockage，and based on comprehensive analysis of accidents about the filling pipeline blockage，the fault tree model about filling pipeline blockage is established by using fault tree analysis of safety system engineering.By calculating minimal cut set，minimal path set and analyzing structure importance of basic event，the main factors influencing filling pipeline blockage are found out.The results show that there are 22 ways leading to the filling pipeline blockage，for example，objects fallen into，grizzly damage and improper pipe diameter，and 4 ways of preventing the filling pipeline blockage，including reasonable control of slurry ratio，elimination of management deficiencies，specifications of relevant design; Unreasonable amount of cement，unreasonable slurry ratio，more elbow and other 16 factors are the most important factors leading to the filling pipeline blockage.Fault tree analysis can make a comprehensive description about various factors which lead to filling pipeline blockage and the logical relationships among them.According to the structure importance，some corresponding prevention measures are put forward.It provides a reliable reference for safety management of filling pipeline.

Key words: Fault tree analysis, Filling pipeline blockage, Minimal cut set, Minimal path set, Structure importance