The invention belongs to the technical field of the mechanized remediation of grasslands, and relates to a combined remediation method for deteriorated grasslands and a special grassland operating machine. The method comprises the following steps of: cutting roots of grass on the grasslands to be remediated, and loosening soil underground and forming seed furrows and fertilizer furrows in the soil along cutting joints; sowing and fertilizing alternately, and applying seeds and fertilizers into the corresponding furrows; and compacting the furrows. The special grassland operating machine comprises a cutting assembly, a vibratory soil loosening and furrowing assembly, a seed and fertilizing applying assembly, a compaction assembly and a depth limit assembly. By the combined remediation method and the special grassland operating machine, the root cutting, vibratory soil loosening and furrowing, sowing, fertilizer application and compaction are combined, and multiple remediation modes are combined, so the combined remediation method and the special grassland operating machine are suitable for the sowing for fertilizer application and fertilizing for resowing in the process of remediating the deteriorated grasslands with high compactness and are also applicable to farmlands with poor soil texture, and can better remediate grasslands deteriorated naturally or due to man factor.