With the requirements of circuit breaker’s insulation and arc-interruption characteristics tests, a modular multifunctional experimental platform is designed in this paper. The designed experimental platform takes the insulation and arc-interruption characteristics of the dielectrics in vacuum chamber and gas chamber as the experimental subjects; taking impulse generator, DC voltage source, frequency current source, and pulse source as the peripheral circuit. Each parts of peripheral circuit are connected with master control desk by sub-control module. The master control desk detects the temperature, humidity, the moving contacts’ operation moments and movements in the chamber at real-time with sensors. And the tested parameters will be revision timely with the controlled relays and IGBTs. Based on the platform, the dynamic dielectric strength recovery characteristics in hybrid circuit breaker, the interruption characteristics of switches with different working voltage and structures, the dielectric strength recovery characteristics of CO2 gas with different gas pressures and temperatures are tested. The test results prove that, the platform is stable and efficient in the experiments, and the temperature error is within 1 ℃, the operating precisions of actuators is controlled within ±500us