The invention belongs to the technical field of super plasticizers, and discloses a four-arm star polycarboxylic super plasticizer, and a preparation method and application thereof. The four-arm star polycarboxylic super plasticizer has a structure as shown in a formula (I), wherein R is a comb structure long chain containing one or more feature structures of a carboxylate radical, a sulfonate radical and an amide group. The four-arm star polycarboxylic super plasticizer takes four-arm polyamide-amine branching molecules terminated by unsaturated double bonds as a core and comb type structures as arms, and meanwhile, the four-arm star polycarboxylic super plasticizer has the properties of star type molecules and a comb type polycarboxylic super plasticizer. The four-arm star polycarboxylic super plasticizer disclosed by the invention has an electrostatic adsorption function provided by a comb type super plasticizer based on the carboxylate radical and the sulfonate radical, a steric hindrance function of a polycarboxylic super plasticizer is increased to a certain degree, and very good liquidity and very good slump-retaining performance. An obtained product is low in mixing amount, high in water reducing rate, good in dispersion performance and good in slump-retaining performance.