The invention discloses a high-titanium high-niobium submerged arc surfacing flux-cored wire. A core wire of the flux-cored wire comprises an alloy component, a first active agent and a second active agent, wherein the first active agent is composed of magnesium oxide, silicon calcium barium aluminum alloy and calcium fluoride; the second active agent is composed of cerium oxide, erbium oxide, manganese silicate, potassium fluoborate, potassium carbonate and sinter of potash water glass; the deposited metal of the flux-cored wire contains 1.8-4.0wt% of Ti, 0.8-3.0wt% of Nb and 1.0-6.0wt% of V. A preparation method of the flux-cored wire comprises the following steps: (1) preparing a core wire raw material and controlling the particle size below 60 meshes; (2) mixing and then sintering all the components corresponding to the second active agent and crushing into materials below 60 meshes; (3) uniformly mixing the alloy component, the first active agent and the second active agent and loading into a steel belt, and preparing into the surfacing flux-cored wire. The high-titanium high-niobium submerged arc surfacing flux-cored wire has the advantages of high surfacing alloy hardness, fine grains, excellent abrasive resistance, excellent toughness, low crack sensitivity, and capability of boosting the wide application of the high-titanium niobium vanadium combined enhanced submerged arc surfacing flux-cored wire.