Compound phosphorus-free reverse osmosis scale inhibitor

The invention belongs to the field of water treatment reagents, and particularly relates to a compound phosphorus-free reverse osmosis scale inhibitor. The compound scale inhibitor is prepared from adendrimer-like polymer, disodium polyepoxysuccinicate, sodium poly-aspartate, IA-AMPS and water, wherein the dendrimer-like polymer is obtained by performing Michael addition reaction on pentaerythritol and acrylonitrile under an alkaline environment, performing esterification reaction on a Michael addition reaction product and an alcoholic compound under an acidic condition and performing reaction on an esterification reaction product and a diamine compound under an organic solvent; the IA-AMPS is a copolymer formed by performing radical polymerization reaction on itaconic acid and 2-acryloylamino-2-methallyl sulfonate which are used as monomers. The compound phosphorus-free reverse osmosis scale inhibitor can solve the problem that an existing organic phosphine scale inhibitor and an anionic polymer scale inhibi