The invention, which relates to the video image processing field, discloses a coding method and apparatus for a composite video broadcast signal. The method comprises: pretreatment is carried out on a brightness signal needing coding and a chroma signal needing coding, wherein the pretreatment includes steps of carrying out brightness comb filtering on the brightness signal needing coding and/or carrying out chroma comb filtering on the chroma signal needing coding; and according the brightness signal and the chroma signal after pretreatment, a composite video broadcast signal is generated. According to the invention, before the composite video broadcast signal is generated, comb filtering is carried out on the brightness signal needing coding and/or chroma signal needing coding, so that a brightness-chroma crosstalk that is caused because a brightness signal is inserted into a chroma spectrum or a chroma signal is insertd into a brightness spectrum can be eliminated automatically, efficiently, and completely.