The MFTA software provides a computer-aided tool for the reliability engineers to analyze multi-state system. Designed on the platform of Windows 95, it has friendly interface. The software used TreeView component to input the logic tree, used StringGrid component to input the judgment table directly. What is more, it can fulfil the conversion of logic models from typical structure function to judgment table automatically. Based on Standard Template Library of C+ + Builder, the library of cube class, upon which the Cube Theory-based MFTA algorithms and analysis methods are implemented, has been developed. The software can be used successfully in the multi-state system reliability analysis.