It is difficult to finish fully and professional testing about frequency converter sets when it was broken or repaired. Aimed at this problem, monitoring system for frequency converter sets is designed. Its hardware circuit is based on IPC platform and PCI bus and software platform is based on Visual Basic and VI (Virtual instrument) technology. It can finish controlling the work status and checking voltage, power etc. and temperature of key parts real-time about the set. Simultaneously it can give an alarm when the status is abnormal. Its results has characteristics of high reliability, high speed and intuitionistic. So it can improve efficiency of test system maximum and save repair expenditure. The system helps for improving reliability of gas turbo-generator set and power quality.