The invention provides an SIR testing system, comprising a control box; a programmable high voltage power supply in connection with the control box to provide power supply to the control box; an industrial personal computer in connection with the programmable high voltage power supply to control the programmable high voltage power supply; a programmable switch in connection with the control box to realize the switching among a plurality of testing channels; a switchboard connected with the control box, the industrial personal computer and the programmable switch respectively to provide a signal channel; an externally provided box in connection with the programmable switch; an environmental test chamber in connection with the industrial personal computer and an ammeter in connection with the control box to measure. Compared with the prior art, the testing system of the invention has the following advantages: 1) simplifying repetitive testing procedures; 2) avoiding errors of manual measurement; and 3) conducting more advanced data analysis.