According to the failure data of a certain type of artillery servo system, the reliability of the artillery servo system was analyzed. By means of failure modes and effect analysis (FMEA), the main reasons for the failure of artillery servo system are obtained through the statistical analysis of the existing failure modes and causes, and the corresponding improvement measures are put forward; According to the results of FMEA, the fault tree of artillery servo system is established, and the minimum cut sets of artillery servo system faults are calculated, which are divided into six categories, and the improvement measures are proposed for different types of bottom event faults. The results show that the analysis can provide data support for improving the reliability of artillery servo system, and provide theoretical basis for the design and preventive maintenance of artillery servo system.