The invention discloses a preparation method and an application of a Pd-Ni bimetallic catalyst supported by N-doped acid-activated sepiolite. The preparation method comprises the following steps: sepiolite is subjected to acid activation or acid modification firstly, then subjected to N-doping treatment and subjected to impregnation to support Ni and Pd. Non-noble metal Ni is taken as a dominant active component and is modified with a small amount of Pd for preparation of the Pd-Ni bimetallic catalyst, so that noble metal is prevented from being used as the only active component, the cost of the catalyst is reduced greatly, a technology for preparing cyclohexanone-oxime from nitrocyclohexane through liquid-phase hydrogenation is enabled to be more environment-friendly by means of the catalyst, the technology is simple, conditions are mild, and quite high nitrocyclohexane conversion rate and cyclohexanone-oxime with high selectivity can be obtained by optimizing the reaction conditions and preparing the catalyst.