Abstract: The power conditioning system (PCS) which provides matched pulse energy for amplifier is a subsystem of a solid-state laser facility. Some catastrophic faults such as capacitor internal short-circuit, bus bar breakdown to ground or high voltage cable short, may occur in the PCS due to the process of charging and discharging which involves high voltage and huge current. To analyze these cases, firstly, the models of the PCS and three main faults are proposed. Secondly, the nonlinear effect of xenon lamp for system model is analyzed based on simulation results and a fixed model with compensation parameter is presented, the experiment results has verified the effectiveness of the fixed model. At last, the tolerance and safety of key components such as damping inductors, capacitors, ballast inductors, are analyzed when faults happened. As a result, the proposed model provides some necessary support for parameter design and fault protect of PCS.