Improvement　of　high-temperature　mechanical　properties　of　W-Cu　based　composites　is　highly　desirable　but　still　a　challenge.　Here　it　is　achieved　by　combined　effects　of　solid　solution,　dispersed　nano-precipitation　and　highly　stabilized　nanostructure　in　the　W-Cu-Cr-ZrC　composite,　which　takes　advantage　of　the　in-situ　precipitated　Zr-Cr-C　nanoparticles　and　phase-separated　Cr　thin　films.　The　grain　size　of　W　phase　in　the　W-Cu-Cr-ZrC　composite　retained　at　the　nanoscale　up　to　1000　degrees　C　(close　to　Cu　melting　point)　for　a　long　duration.　The　high　thermal　stability　of　the　nanostructure　endows　the　composite　with　a　compressive　strength　of　1150　MPa　at　900　degrees　C,　which　is　approximately　four　times　as　high　as　that　of　the　binary　coarse-grained　W-Cu　composite.　The　effects　of　microstructure　evolution　on　the　mechanical　properties　at　high　temperatures　and　its　mechanisms　were　disclosed.　The　results　indicated　the　crucial　role　of　the　microstructural　stability　of　W　phase　skeleton　in　the　overall　strength　of　the　W-Cu　based　composites.