The invention discloses a testing device and a testing method for studying influence of rainfall of dusty weather on electronic puncture voltage. The testing device includes a rainfall test box and a test circuit; the rainfall test box comprises a box body, a rainfall nozzle, a supporting insulator and an electrode bracket; the rainfall nozzle is located at the top end of the box body, and the supporting insulator is fixed at the bottom part of the box body; the electrode bracket is fixed on the supporting insulator; the test circuit includes a voltage regulator B, a transformer T, a protective resistor R and a capacitive voltage divider F. Influence of the rainfall of dusty weather on puncture voltages at different gaps in actual electrifying running can be exactly obtained.