A transient current suppression device, which is applied to a fan, includes a filtering circuit, a delayed turn-on circuit and a forcibly electrical discharging circuit. The filtering circuit outputs a first voltage signal and a first current signal according to a first power signal. The delayed turn-on circuit is electrically connected with the filtering circuit. The delayed turn-on circuit provides a first discharging path for the first current signal according to a second power signal after a delayed time and outputs a second current signal. The forcibly electrical discharging circuit is electrically connected with the delayed turn-on circuit and the filtering circuit. The forcibly electrical discharging circuit provides a second discharging path for the second current signal according to the first voltage signal. Hence, the transient current suppression device can suppress the transient current effectively and rapidly.