The invention discloses a metal or ceramic consumable item for FDM 3D printing, a preparation method for the metal or ceramic consumable item and a finished product printing method. The metal or ceramic consumable item comprises, by weight, 15-50 parts of a high polymer material, 0-2 parts of a compatilizer, 50-80 parts of metal powder or ceramic powder, 0.1-1 part of an antioxygen and 0.1-2 parts of a lubricating agent. The cost for equipment, the materials and machining is low; a printing structure is free of limitation, collapsing conditions do not exist in the printing process, supports can be removed before fusion sintering of the product, and treatment is easier compared with a manner that the supports are removed after SLS or EBAM fusion sintering; the requirements for the sphericity degree, the size distribution, the mobility and the like are relatively low; the types of metal and ceramic capable of being printed are wider; and the density of the finished products is higher, the strength is high, the degree of finish is higher, the miniaturization capacity is high, the thin-wall capacity is high, the complexity is high, the design tolerance level is high, and the material adaption scope is wide.