The effects of the spark plasma sintering temperature on microstructure and dynamic mechanical properties of the tungsten heavy alloy with nano-crystalline 93W-4.9Ni-2.1Fe alloy powder as raw material were investigated. Results show that ultra-fine tungsten alloy with uniform microstructure can be prepared by the spark plasma sintering technology. In the sintering temperature range between 950 oC and 1400 oC, the average particle size of the tungsten heavy alloy increases from 2 μm to 10 μm with the sintering temperature elevation while the dynamic compressive strength decreases accordingly. During the process of dynamic compression the plasticity of samples sintered at the temperature between 1000 oC and 1200 oC is good. However, dynamic plasticity of samples sintered at the temperature between 1300 oC and 1400 oC is almost zero, showing typical brittle failure