The high current linear induction accelerators (LIA) is mainly made for advanced radiography which is the most important test method in hydrokinetics study. The required reliability of the whole test system is very high. The pulsed power system of LIA is very huge and complex. It includes several different kinds of high voltage equipment. There are some possibilities of self-excitaion for the equipment when they are charging or waiting after charged. If self-excitaion happens and no measure is taken, radiographic test would be unsuccessful, and heavy economic loss and bad effect are ineluctable. A method of improving the reliability of advanced radiography is developed based on monitoring the self-excitation of pulsed power system. Passive detector with high reliability for high voltage pulse discharging is first developed based on a certain extent linear principle and several type of detectors are also developed for different discharging equipment. Programmable large scale integrated circuits (LSIs) are adopted to make up of the logic processor in the system to improve the system integration degree, to simplify the circuit and to reduce the debugging difficulty. The monitor and controller system can be easily extended to meet more lines monitor demand. The fast response of the system is about hundred nanoseconds. Its anti-jamming ability can fully meet the demand of the radiographic test environment condition and achieve the goal of improving the the reliability of advanced radiography.