For an optimized formula of the cementing agent good for formation, the viscosity and rheological properties of 93W-Ni-Fe PEM feeds with the same powder loading but four kinds of binder composition systems which were called A, B, C and D feedstocks were studied. By the British AR2000EX rotary rheometer, the viscosity of the tungsten-based alloy PEM feed at different shear rates and different temperatures were measured. The results indicate that among the four feedstocks, A has a low viscosity and good flow properties. The rheological properties of D feed are the most unstable. According to their relationship curves between viscosity and shear rate at the 130 oC, the shear-thinning index of A, B and C feeds can be calculated as 0.048, –0.869 and –1.717, respectively. According to the relationship curves between viscosity and temperature at the shear-rate of 11.07 s-1, the flow activation energy of A, B and C feeds can be calculated as 8.524, 8.107 and 31.310 kJ·mol-1, respectively. Through simulation, at 130 oC and the shear-rate of 11.07 s-1, the liquidity index of A, B and C feeds is 7.2×10-6, 4.8×10-6 and 1.1×10-6, respectively. The comprehensive rheological performance of A feed is the best.