The invention provides an environment-friendly natural dye dyeing method of a silk fabric. A mordant with a good effect is prepared from allanite, organic acid and graphene, and therefore a color fixing effect of natural dyes can be effectively improved; meanwhile, in the overall dyeing and mordant preparing process, a large quantity of chemical substances do not need to be added, therefore, the usage amount of various chemical reagents is greatly decreased, environmental pollution is reduced, and the healthy and environment-friendly requirements of the country on textile industry are met.