Abstract: In this paper,the influence of temperature and time of the vacuum heat treatment on the mechanical properties of the 90W-7Ni-3Cu alloy and the relafionship between its hydrogen contents and mechanical properties are investigated.Experiment results showed that vacuum heat treatment could lower hydrogen contents and improve mechanical properties of the alloy.While hydrogen content was lowered from 7.3ppm to 3.6ppm,the ultimate tensile strength increased by 18% and the elongation increased by 4 times.