The invention provides an abrasion-resistant cast iron plate part surface treatment method and application thereof. The abrasion-resistant cast iron plate part surface treatment method comprises the steps that firstly, a cast iron plate is infiltrated with a carbonitride lanthanum yttrium ion infiltrating agent; the treated cast iron plate is activated with a lanthanum yttrium activation infiltrating agent; oxygen ion infiltrating is carried out with an oxygen ion infiltrating agent; and then, after cooling and cleaning are carried out, sealing treatment is carried out with a sealing agent, and soaking in oil is carried out. According to the abrasion-resistant cast iron plate part surface treatment method and the application thereof, the carbonitride lanthanum yttrium ion infiltrating agent is firstly used for infiltrating treatment to form a compound layer and diffusion layer with a certain thickness, the compound layer and the diffusion layer are composed of a carbonitride compound of metal elements and a solid solution of nitrogen in iron, the hardness and corrosion resistance are higher, the thickness of a compound infiltrating layer is increased, and the fatigue resistance ofthe plate is improved. According to the abrasion-resistant cast iron plate part surface treatment method, the temperature is low, the plate does not deform in the treatment process, the processing precision is not affected, and the effective infiltration of carbonitride lanthanum and yttrium ions can be ensured under a low temperature condition. The application of the surface treatment method in steel backing machining is further provided.