—Lightning protection for power supply of electronic equipment is an important problem of low-voltage lightning protection systems. In this paper, lightning characteristics of electronic equipment’s power supply are studied. Firstly impulse generator is developed. Then lightning characteristics tests for different powersupply, such as switch model power supply, are done. Test results show: different power supply has different lightning impulse characteristics.Usually two different models are used for lightning performance evaluation: common and different model. Both impulse current and impulse voltage withstand capability in common model are stronger than those in different model. Flashover often occurs in the AC-DC conversion part inside of the switch power supply when there is lightning stroke. The manufacturing technology of the power supply has definite effect on withstand capability. The switch model power supply has some weak parts when there is lightning stroke, such as tran...