The invention relates to a flame-retardant anti-counterfeiting paper preparation method, which can effectively solve the problems of easy burning, easy imitating and insufficiently-high fluorescence intensity of the existing anti-counterfeiting paper. The method comprises: under N2 protection, adding tellurium powder and sodium borohydride to ethanol and water, heating, carrying out a reaction to produce sodium tellurium hydride, adding dilute sulfuric acid, absorbing the generated hydrogen telluride by using a sodium hydroxide solution to generate a sodium tellurium hydride solution, injecting the sodium tellurium hydride solution into a thioglycolic acid stabilizer and a cadmium chloride aqueous solution under stirring, carrying out heating reflux, sampling at different reflux times to obtain the suspensions of CdTe quantum dots having different particle sizes and different emission wavelengths, adding a dissolved paper pulp, ammonium polyphosphate, zinc borate, aluminum hydroxide and phosphoric acid to water, respectively adding the CdTe quantum dot suspensions obtained at different reflux times, stirring, carrying out papermaking with a paper machine, and drying to obtain the flame-retardant anti-counterfeiting paper. According to the present invention, the flame-retardant anti-counterfeiting paper has advantages of rich raw material, simple preparation method, easy production, low cost, good anti-counterfeiting effect, good fire resistance, energy saving, and environmental protection.