The present measurement system is composed of signal preprocessors, an A/D conversion card, optical fibers, a microcomputer, and an interface. After discharge parameters of an ion source at high potential, i.e., analog signals, are preprocessed by means of LPF, amplitude limit, and normalization, they are changed into digital signals by A/D conversion. The digital signals are transferred through optical fibers to low potential, then they are gathered, processed, or stored by the microcomputer. The system can measure eight analog signals at high potential through scanning. Each measurement will take about 160 &mgr;s with a precision of ±1 LSB, i.e., ±0.4% maximum relative error at full range. Measurements of discharge parameters of the ion source at high potential were made for a steady state ion source and a high current pulse ion source successively, whose results are in good agreement with practical cases. The formation and propagation of interference and approaches of anti‐interference under high current and high pulse voltage conditions are briefly described in the present article.