The invention provides a ferrite material and a preparation method thereof. The ferrite material comprises, by mole, the following main formula components: 30-35% of ZnO, 45-50% of Fe2O3, 10-19% of NiO and 10-20% of MnO2. Based on a main formula, and additive is prepared from, by mass, the following components: 0.06% of Nb2O5, 0.04% of Bi2O3, 0.1% of V2O5 and 0.025% of TiO2. A high-frequency current sensor prepared from the material has strong response to electric signals released by partial discharge, can be applied to partial discharge detection of cables, has high sensitivity, can detect weak discharge in the cables in time and can inhibit further damage of the partial discharge to the cables in time.