Abstract: According to the requirements of steel containment vessel leakage test of nuclear power plant, the integrated leakage rate testing system which is based on the LabVEIW software platform and the Compact-RIO embedded system is developed. The design of system is simplified using digital communication, RS-485 bus, separation of collection and analysis,by which the system is simplified and the reliability and extensibility are enhanced. The system is used and verified in the steel containment vessel integrated leakage rate test of AP1000 nuclear power plant, the field test and verification show that the system has stale and reliable operation, high accuracy of calculation and measurement, and can meet the requirements of integrated leakage rate test. The system have already used in all steel containment vessel integrated leakage rate test of domestic AP1000 NPPs.