Aiming at solving the problem of poor strength, low conductivity and thermal conductivity of Cu-W alloys, high pressure aging treatment was conducted to reinforce Cu-51.15W-0.24Cr alloy. The microstructure, hardness, thermal conductivity and conductivity of the alloy after high pressure aging treatment and normal pressure aging treatment were compared. The results show that high pressure aging treatment can increase the compactness of Cu48.61W51.15Cr0.24 alloy, eventually resulting in more dispersed distribution and finer grain size of Cr phase during the aging treatment, and improving the hardness and thermal conductivity of the alloy. After solution treatment at 960 °C for 1 h and aging at 500 °C for 1 h under a pressure of 3 GPa, the hardness, thermal diffusivity and resistivity are determined to be 1540 MPa, 0.5236 cm²·s^-1 and 4.458×10^-8 Ω·m, respectively, which are 17.56% and 10.74% higher than and 4.85% lower than those of alloy under normal pressure, respectively. Therefore, high pressure aging treatment can be an effective way to improve mechanical properties and to reduce resistivity of Cu-51.15W-0.24Cr alloy.