The invention discloses a preparation method of a waterborne polyurethane coating for wooden furniture for children. The preparation method comprises the following steps: mixing oxidized polyethlene wax, potassium metabisulfite and deionized water, feeding nitrogen for boosting, heating and stirring, cooling, adding aluminium nitrate, boracic acid and disproportionated rosin 6000 and stirring, dropwise adding ammonia water, carrying out hydrothermal reaction, calcining, cooling and pulverizing to obtain a material a; uniformly mixing polyurethane prepolymer, acrylic modified epoxy resin, glycidyl methacrylate, light calcium carbonate, the material a, the disproportionated rosin, epoxidized soybean oil, a wetting agent, cottonseed oil and the like, grinding, then adding gangue, titanium dioxide microspheres, carbon nanotubes and zeolite powder and stirring uniformly, adding hollow glass microspheres and stirring uniformly, and filtering to obtain a material b; uniformly mixing triallylisocyanurate, dimethyl benzylamine, ethylene glycol monobutyl ether acetate, texanol and deionized water to obtain a material c; and uniformly mixing the material b and the material c, and standing toobtain the waterborne polyurethane coating for the wooden furniture for the children.