According to Reliability issues with hydro-pneumatic suspension, the method of combining failure mode and effect analysis (FMEA) and fault tree analysis (FTA) is proposed for research and analysis on system reliability. By analyzing the function and composition of stationary hydro-pneumatic suspension, FMEA table is given. From the perspective of system design, the fault tree of gasbag crack is built, and improvements to major weaknesses are suggested. It is shown that gasbag reliability improvement methods are effective in full-scale experiments. The significantly increase of fixed hydro-pneumatic suspension reliability is achieved.