The invention relates to a preparation method of an attapulgite/aqueous polyurethane compound binder, belonging to the field of organic binders and comprising the following steps of: (1) modified polyurethane prepolymer preparation: vacuumizing hydroxy monomers and hydrophilic monomers at the temperature of 90 DEG C under the vacuum degree of 0.09-0.1MPa, then adding metric isocyanate monomers onthe basis of regulating the prepolymerizing temperature to 65-90 DEG C, and controlling the R value at 1.02-2.0; (2) prepolymer neutralization and dispersion: lowering uniform temperature by 40-70 DEG C on the basis of the first step, and adding a neutralizer to neutralize into salt; after 30 minutes, controlling the solid content at 20-40 percent; dispersing metric attapulgite suspension into salt-formation modified polyurethane prepolymer and stirring at high speed for 30 minutes to prepare an attapulgite/aqueous polyurethane compound emulsion; and (3) chain extension stage: adding an chainextender on the basis of the second step, and continuously stirring for 30 minutes and discharging to prepare a final product of the emulsion of the attapulgite/aqueous polyurethane compound binder. The compound binder can be made into an artificial board which has excellent performance and meets the environmental protection requirements.