The invention discloses a preparation method of light-resistant and waterproof water-based flame retardant polyurethane coating and adhesive. The preparation method of the light-resistant and waterproof water-based flame retardant polyurethane coating and adhesive comprises the following steps: mixing polytetrahydrofuran glycol with isophorone diisocyanate in the presence of a fullerene catalyst, reacting at the temperature of 60-85 DEG C for 1-2 hours, adding coumaphos and propantheline bromide, and reacting at the temperature of 70 DEG C for 3 hours, so that polyurethane prepolymer A is obtained; adding a chain extender, butanone and riboflavin sodium phosphate into the polyurethane prepolymer A, reacting at the temperature of 60-85 DEG C for 2.5-3.5 hours, adding a flame retardant, reacting at the temperature of 75-85 DEG C for 1-2 hours, then adding 1,4-dihydroxy anthraquinone, polyacrylamide and a tackifying agent, reacting at the temperature of 75 DEG C for 1-2 hours, then adding triethylamine and carrying out neutralization reaction for 30-50 minutes, adding water and emulsifying for 30 minutes, so that the light-resistant and waterproof water-based flame retardant polyurethane coating and adhesive are obtained. The prepared light-resistant and waterproof water-based flame retardant polyurethane coating has triple performance of flame retardance, light resistance and water resistance; meanwhile, polyurethane is environment-friendly and low in cost, so that the prepared light-resistant and waterproof water-based flame retardant polyurethane coating can be widely applied to surfaces of a wall body, furniture and metalware; the prepared light-resistant and waterproof water-based flame retardant polyurethane adhesive can be taken as a binder for plastic, glass, paper, textiles and leather.