Phase　separation　at　nanoscale　and　highly　dispersive　nanoparticles　were　exploited　to　fabricate　a　novel　type　of　nanocrystalline　W-Cu-Cr-ZrC　composite　with　special　hierarchical　structure.　The　microstructures　were　characterized　elaborately　and　the　formation　mechanisms　of　the　hierarchical　structure　were　disclosed.　It　was　found　that　the　supersaturated　Cr　separated　from　W　during　sintering　and　segregated　at　profuse　interfaces.　Moreover,　Cr　can　also　interact　with　ZrC　nanoparticles　dispersed　in　W　matrix,　leading　to　the　formation　of　Zr-Cr-C　phase　which　exerts　significant　effect　on　inhibiting　coarsening　of　W　grains.　On　the　other　side,　the　dissolution　of　Cr　and　W　contributes　to　the　formation　of　Cu　nanocrystalline　structure.　As　a　result,　the　prepared　W-Cu-Cr-ZrC　composite　exhibits　an　ultrahigh　hardness　of　943HV　owing　to　the　synergy　of　nanocrystalline　structure　and　dispersion　strengthening　of　nanoparticles.　The　hardness　has　achieved　the　highest　value　among　the　W-Cu-based　composites　with　the　same　Cu　content　reported　in　literature.　This　study　provided　a　new　strategy　for　production　of　high-performance　W-Cu-based　composites　through　combination　of　microstructural　design　with　addition　of　doping　element　and　nanoparticles.