Fine-grain 93W-4.9Ni-2.1Fe+0.03%Y alloy was fabricated by microalloying and liquid phase sintering process. The effects of the annealing temperature on the microhardness and microstructure evolution of the fine-grain 93W-4.9Ni-2.1Fe+0.03%Y after rapid hot extrusion were investigated. Meanwhile, conventional tungsten heavy alloy was also fabricated at equivalent condition for comparison. The results show that the microhardness of tungsten phase of the alloys is severely decreased with the annealing temperature increasing. EDS examination reveals that the tungsten content in the matrix of tungsten heavy alloys is gradually enhanced with elevated annealing temperature. The tungsten content in the matrix of fine-grain tungsten heavy alloy has reached a maximum level of the order of 26.11% after annealed at 1200 °C. While, the tungsten content in the matrix of conventional tungsten heavy alloy annealed at the temperature of 1350 °C is 28.14%. Microstructure observation shows that annealing treatment is preferential to the tungsten contiguity reduction and tungsten grain refinement. After high temperature annealing, the matrix is distributed more homogeneously and the volume fraction of the matrix of fine-grain tungsten heavy alloy is higher than that of coarse-grain alloy