As the 'heart' of high-current vacuum electronic devices, explosive emission cathodes play an important role in their applications. In this work, a titanium dioxide (TiO 2 )/carbon fibre cathode prepared by a cold atmospheric plasma jet is reported. TiO 2 on the carbon fibre surface prepared by an atmospheric plasma jet is at the mixture of anatase and rutile phases. The field enhancement factor of the TiO 2 /carbon fibre cathode is 6681, which is over ten times higher than that of the carbon fibre cathode. Furthermore, the TiO 2 coating slows the diode impedance collapse and decreases the cathode plasma expansion velocity from 1.5-2.0 to 1.0-1.5 cm µs −1 , which is explained by a cathode plasma model. The surface of the TiO 2 /carbon fibre cathode is covered by 1.6 cm 2 plasma, far exceeding that of the carbon fibre cathode (1.1 cm 2 ), which enables uniform explosive electron emission. The obtained results show that TiO 2 /carbon fibre cathodes prepared by cold atmospheric plasma jets will be potential candidates as high-current explosive electron emitters.