Abstract ZrW2O8-Cf/E51 composite with a negative Coefficient of Thermal Expansion (CTE) was fabricated by a method combining mechanical stirring with ultrasonic vibration, then microstructures and properties of the composites were analyzed and summarized by scanning electron microscope (SEM), DIL 402 C thermal expansion tester and electronic universal testing machine. The results showed that particles distribution defects and impregnation defects of carbon fibers would occur when the process parameters were not controlled properly. Long curing time and good fluidity of resin were beneficial for resin impregnating carbon fibers and bubbles overflow. However, for the ZrW2O8-Cf/E51 composites studied in this paper, long curing time and low viscosity could cause particle settling and accumulation. The experimental results confirmed that the CTE (about −0.52 × 10−6/°C) and tensile strength (about 440 MPa) of E51 resin were improved with the addition of carbon fibers and ZrW2O8 particles.