The invention discloses a method for preparing a tungsten-molybdenum-copper composite material through spark plasma sintering. The method comprises the steps that tungsten powder, molybdenum powder and copper powder are sufficiently ball-milled and evenly mixed at first, the evenly mixed powder is placed in a graphite mold, then the graphite mold is placed in a reaction chamber, and the tungsten-molybdenum-copper composite material is prepared at a low temperature through a specific thermal treatment process. The method for preparing the tungsten-molybdenum-copper composite material through spark plasma sintering is provided for solving the problems of an existing melting and infiltration method for preparing a tungsten-molybdenum-copper alloy; and compared with the existing melting and infiltration method, the method has the advantages that the preparation temperature can be lowered from 1100-1600 DEG C to 750-1050 DEG C, the preparation time is shortened from 100-760 min to 15-45 min, the tungsten-molybdenum-copper composite material can be prepared without a secondary thermal process that a tungsten-molybdenum framework is prepared before high-temperature copper infiltration, the process is simplified, the method is easy to implement, and products which are small in grain and tightly combined can be obtained. The defects that an existing sintering method is high in sintering temperature, long in sintering time, complex in process and the like are overcome.