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The MoNbTaW refractory high-entropy alloys were prepared by spark plasma sintering using pure metal powders as raw materials. The effects of technological parameters on the phase, crystal structure, sintering behavior and mechanical properties of MoNbTaW refractory high-entropy alloys were studied. The results show that the single-phase BCC high-entropy alloy can be formed at the sintering temperature of 1800 °C with the holding time of 5 min. The sintering temperature is the most important factor that affects the density, grain size and mechanical properties of the MoNbTaW refractory high-entropy alloy. When the sintering temperature is 2000 °C, the density of the alloy is 99.8 %, and the yield strength is 1314±14 MPa, the fracture toughness is (5～6)MPa.m_1/2. The MoNbTaW refractory high-entropy alloy prepared by spark plasma sintering process have no chemical composition segregation and is a brittle material with the fracture mode of cleavage fracture.