Abstract: To analyze the influences of parameter uncertainty on system reliability, a system reliability sensitivity analysis method based on the sequential compounding method (SCMSA) is proposed. The SCMSA makes use of the principle of SCM combination element, and further calculates the equivalent correlation coefficient between the two components and other remaining components in the system on the basis of calculating the reliability and sensitivity of a simple system with two components in parallel or in series, so as to achieve the purpose of combining the two components and simplifying the complex system. The advantage of SCMSA is that it integrates the calculation of the relative sensitivity index into the system reliability analysis, so that the sensitivity analysis can be calculated together as a byproduct of the reliability analysis, and this method can be applied to the system reliability sensitivity analysis of the relative non-normal variables. Finally, a simple numerical example is used to illustrate the calculation process, calculation accuracy and calculation advantage of SCMSA, and it is applied to the sensitivity analysis of a system reliability of semi-gravity retaining wall, indicating that the SCMSA can provide a theoretical basis for the risk analysis and prevention of geotechnical engineering.