Welding wire and welding flux for 1000MPa-grade high-strength steel large linear energy submerged-arc welding and preparation method and welding method of welding wire and welding flux

The invention discloses a welding wire and a welding flux for 1000MPa-grade high-strength steel large linear energy submerged-arc welding, a preparation method and a welding method, and belongs to the technical field of welding materials and preparation thereof. The method solves the problems of low-temperature toughness reduction, alloy element burning loss, unstable electric arc, high crack sensitivity and the like of the existing 1000MPa-grade high-strength steel adopting high linear energy submerged-arc welding. By regulating and controlling the components of the welding wire and the welding flux, the welding wire and the welding flux can be used for welding 1000MPa-grade high-strength steel under large linear energy, weld metal obtained through tests is attractive in forming and good in straightness, the tensile strength of the weld metal is larger than or equal to 950MPa, the yield strength of the weld metal is larger than or equal to 820MPa, the impact absorption energy of the weld metal in a Charpy pe