The invention discloses a palladium-based catalyst. The palladium-based catalyst is characterized in that composite oxide prepared by zirconium dioxide and activated aluminum oxide and modified by lithium is used as a supporter, palladium is used as a main active component, one or more of magnesium, calcium, lanthanum, cerium, ferrum, cobalt, nickel and zinc is selected as an assistant active component, the mass ratio of zirconium dioxide ZrO2 and activated aluminum oxide AlO2O3 is 1: (1-40), the mass content of lithium in the supporter is 0.1-20%, the mass content of palladium in the catalyst is 0.02-10%, and the mass content of the assistant active component in the catalyst is 0-8%. Compared with the prior art, the catalyst is obviously improved in the aspects of activity, wearing resistance and anti-hydration performance.