A preparation method of a Cu-nano WC composite material, wherein the Cu-nano WC composite material meets the following conditions: in a weight ratio, Cu powder: WC powder=98:2~30:70; the Cu powder is of -200 meshes and has a purify of ≥99.7%, and the WC is <500 nano and has a purity of ≥99.0%; the process comprises the following steps: S1) powder mixing process: Cu powder and WC are mixed in the above ratio and then the obtained mixed powder and steel balls are mixed for 3-10 h in a weight ratio of mixed powder to steel balls of 100:100; S2) loose sintering process: the uniformly mixed powder is loosened into a graphite crucible and subsequently subjected to vacuum sintering; when a vacuum degree reaches 5 × 10 -2 pa level or below, the obtained product is preserved for 2 h at 950-1050 °C so as to complete sintering, thereby obtaining a Cu-nano WC body; S3) burdening process: the Cu-nano WC body subjected to loose sintering and oxygen-free Cu blocks are burdened in a weight ratio of Cu to WC of 99:1~50:50; S4) vacuum induction melting process: the prepared Cu-nano WC body and the oxygen-free Cu blocks are put in a ceramic crucible, a vacuum system of vacuum induction melting equipment is opened, the above reactants are subjected to gradient heating when the vacuum degree reaches 3 × 10 -1 pa or below, the specific gradient heating process is as follows: 10-20 KW, 1-5 min; 20-30 KW, 1-5 min; 30-40 KW, 1-5 min; 40-50 KW, 1-5 min; subsequently, power is kept at 40-60kw, when the oxygen-free Cu blocks are gradually molten in the crucible, the vacuum system is switched off, an inert protective gas is charged until the vacuum degree is -0.1~0.01 Mpa; S5) cooling process: after all the Cu-nano WC bodies in the crucible are completely dissolved by liquid Cu and are uniform under the action of electromagnetic stirring, the molten liquid in the crucible is poured into a cooling mould to be cooled for 1 h. in a weight ratio, Cu powder: WC powder=98:2~30:70; the Cu powder is of -200 meshes and has a purify of ≥99.7%, and the WC is <500 nano and has a purity of ≥99.0%; the process comprises the following steps: S1) powder mixing process: Cu powder and WC are mixed in the above ratio and then the obtained mixed powder and steel balls are mixed for 3-10 h in a weight ratio of mixed powder to steel balls of 100:100; S2) loose sintering process: the uniformly mixed powder is loosened into a graphite crucible and subsequently subjected to vacuum sintering; when a vacuum degree reaches 5 × 10 -2 pa level or below, the obtained product is preserved for 2 h at 950-1050 °C so as to complete sintering, thereby obtaining a Cu-nano WC body; S3) burdening process: the Cu-nano WC body subjected to loose sintering and oxygen-free Cu blocks are burdened in a weight ratio of Cu to WC of 99:1~50:50; S4) vacuum induction melting process: the prepared Cu-nano WC body and the oxygen-free Cu blocks are put in a ceramic crucible, a vacuum system of vacuum induction melting equipment is opened, the above reactants are subjected to gradient heating when the vacuum degree reaches 3 × 10 -1 pa or below, the specific gradient heating process is as follows: 10-20 KW, 1-5 min; 20-30 KW, 1-5 min; 30-40 KW, 1-5 min; 40-50 KW, 1-5 min; subsequently, power is kept at 40-60kw, when the oxygen-free Cu blocks are gradually molten in the crucible, the vacuum system is switched off, an inert protective gas is charged until the vacuum degree is -0.1~0.01 Mpa; S5) cooling process: after all the Cu-nano WC bodies in the crucible are completely dissolved by liquid Cu and are uniform under the action of electromagnetic stirring, the molten liquid in the crucible is poured into a cooling mould to be cooled for 1 h. S1) powder mixing process: Cu powder and WC are mixed in the above ratio and then the obtained mixed powder and steel balls are mixed for 3-10 h in a weight ratio of mixed powder to steel balls of 100:100; S2) loose sintering process: the uniformly mixed powder is loosened into a graphite crucible and subsequently subjected to vacuum sintering; when a vacuum degree reaches 5 × 10 -2 pa level or below, the obtained product is preserved for 2 h at 950-1050 °C so as to complete sintering, thereby obtaining a Cu-nano WC body; S3) burdening process: the Cu-nano WC body subjected to loose sintering and oxygen-free Cu blocks are burdened in a weight ratio of Cu to WC of 99:1~50:50; S4) vacuum induction melting process: the prepared Cu-nano WC body and the oxygen-free Cu blocks are put in a ceramic crucible, a vacuum system of vacuum induction melting equipment is opened, the above reactants are subjected to gradient heating when the vacuum degree reaches 3 × 10 -1 pa or below, the specific gradient heating process is as follows: 10-20 KW, 1-5 min; 20-30 KW, 1-5 min; 30-40 KW, 1-5 min; 40-50 KW, 1-5 min; subsequently, power is kept at 40-60kw, when the oxygen-free Cu blocks are gradually molten in the crucible, the vacuum system is switched off, an inert protective gas is charged until the vacuum degree is -0.1~0.01 Mpa; S5) cooling process: after all the Cu-nano WC bodies in the crucible are completely dissolved by liquid Cu and are uniform under the action of electromagnetic stirring, the molten liquid in the crucible is poured into a cooling mould to be cooled for 1 h.