The invention discloses an internal arcing tolerance test loop of a DC high-speed switch. The test loop comprises a short-circuit loop, a rectification loop and an arcing monitoring loop. The short-circuit loop includes a short-circuit auxiliary circuit breaker, an AC power supply, and a short-circuit transformer; and the AC power supply, the short-circuit auxiliary circuit breaker, and a primarycoil of the short-circuit transformer are connected successively in series to form a loop. The rectification loop includes a first ammeter, a rectifier valve group, an electric reactor, a rectification auxiliary circuit breaker, and a current limiting resistor. Under the coordinated effect of the short-circuit loop, the rectification loop and the arcing monitoring loop, the internal arcing tolerance test scene of the DC high-speed switch can be simulated equivalently. After equivalent loop simulation, the ablation performance of the tolerant system load DC current of the circuit breaker underconditions of false action and hidden jumping of the running state of the system is verified under the rated air pressure of the circuit breaker SF6.