The invention discloses a method for preparing a snow melting and ice inhibiting functional material from saponated residue, and belongs to the technical field of preparation of novel functional materials. The method comprises the following steps: taking the saponated residue as a raw material, carrying out activating treatment by adopting a proper means, and introducing biomass which is abundant in sources as a modification raw material, thus preparing composite micro-capsule snow melting and ice inhibiting filler, wherein the composite micro-capsule snow melting and ice inhibiting filler comprises a carbon quantum dot composite ice point reducing type micro-capsule material agent and double-surface grafted modified snow melting and ice inhibiting filler; grafting a silica-based material to the double-surface grafted modified snow melting and ice inhibiting filler by applying digestion residue through physical and mechanical actions, so as to regulate the surface characteristics of the double-surface grafted modified snow melting and ice inhibiting filler, then introducing a surface modification material for grafting again, and balancing the moisture absorptivity and the salinity separation rate, thus obtaining the snow melting and ice inhibiting functional material having good thermal stability and good mechanical property. Self snow melting and ice inhibiting can be realized at low temperature by two prepared filler materials through a salt effect, an interface energy effect and a contact angle effect, the cost is reduced by utilizing the saponated residue, meanwhile, the treatment problem of the saponated residue is solved, and research and development of the snow melting and ice inhibiting functional material are favorably promoted.