The invention relates to a separation method for C9-C10 fractions. The separation method for the C9-C10 fractions comprises the following steps: carrying out vacuum distillation separation on raw materials in a vacuum distillation tower for obtaining rich phenylethylene and alpha methyl styrene fractions at the tower top and obtaining residual fractions at the tower bottom; enabling tower bottom materials to enter a depolymerization and distillation tower and carrying out depolymerization and distillation for obtaining rich cyclopentadiene fraction at the tower top, methyl cyclopentadiene material at a lateral line and mixed fraction of indene and residual dicyclopentadiene at the tower bottom; enabling tower bottom fraction to enter the vacuum distillation tower and carrying out vacuum distillation for obtaining mixed fraction rich in indene and dicyclopentadiene at the tower top and heavy component impurities at the tower bottom; and enabling fraction rich in indene and dicyclopentadiene to enter the depolymerization and distillation tower and carrying out depolymerization and distillation for obtaining cyclopentadiene fraction at the tower top and fraction rich in indene at the tower bottom. The separation method for the C9-C10 fractions has the advantages that high-purity cyclopentadiene and methyl cyclopentadiene are obtained while a high-quality petroleum resin raw material is obtained; dimerization reaction is greatly reduced in a distillation separation process, so that generation of polymers is avoided, the yield of one-way products is high, and the problem that dicyclopentadiene and indene are difficult to separate is also solved.