Hydraulic support is the necessary equipment of mine production, with important role to mine safe and effective production. The power of hydraulic support is from high pressure emulsion provided by emulsion pump station, once emulsion pump station has fault, the hydraulic support would lose power. Through analyzing common fault types of emulsion pump station, 6 logic or gate, 11 bottom event constructs fault tree. Factors leading to system fault were found out through qualitative analysis, the weak part of the system was found out by quantitative analysis, system reliability was analyzed. Based on the analysis result of fault tree, improving the inspections of seal wear and emulsion pollution, meant a lot for actual working.