Acquiring causal knowledge of abnormity is essential to Missile-Launching reliably. There are lots of Knowledge Acquisition methods. But it is absence for usage and maintenance support process. So it is necessary to start the research on new knowledge acquisition technology of aid Decision-Making for Missile-Launching. Based on the Usage and Maintenance-Support Process, this thesis acquires knowledge with the ESD and CESD (Converse Event Sequence Diagram) method. First, this thesis gives the concept of CESD. Then, in order to adapt the CESD model of the complex systems more effectively, this paper expands the CESD framework and provides a software frame of computer aided ESD study. Finally, the operation of pulse power supply system is analyzed on the basis of the improved ESD and CESD. This sample shows the applicability of ESD and CESD methodology in knowledge acquisition technology of aid Decision-Making for Missile-Launching.