A coating shim and a coating device, for applying a first slurry and a second slurry to an object to be coated are provided. The coating shim includes: a first flow channel for applying the first slurry to the object to be coated to form a first coating layer; and a second flow channel for applying the second slurry to the object to be coated to form a second coating layer. The first flow channel has a first slurry outlet at a first end face of the shim facing the object to be coated, the second flow channel has a second slurry outlet at the first end face, and the first slurry outlet and the second slurry outlet are configured to partially overlap in a thickness direction of the shim, such that the first coating layer and the second coating layer partially overlap in the thickness direction of the shim.