A coating apparatus for a color filter substrate, including a coating sprayer (1) configured to coat a first film layer on a color filter layer (03) formed on the color filter substrate (01); a grinding device (2) configured to grind the color filter layer (03) to eliminate a step formed by the color filter layer (03) covering a black matrix (02); and a detection control unit (3) configured to measure a height of the step, determine a grinding amount of the grinding device (2) according to the height of the step, and control an operation of the grinding device (2) such that the first film layer coated on the color filter layer (03) has a flat surface. Also disclosed is a coating method for a color filter substrate.