Comb-shaped and linear polycarboxylic acid high performance water reducer and traditional STPP and SM are mixed separately into different refractory material.It was studied that how viscosity and suspensibility of kaolin mud,fluidity and water demand for normal consistency of cement paste and fluidity of silica fume paste were affected by different kinds of water reducer and different mechanisms were analyzed.The relative molecular mass and structure of water reducer and particle,activity and shape of refractory material particle have great impact on their compatibility.Appropriate proportion of mixed water reducer is added into designed refractory castable according to the compatibility of different water reducer and refractory material.Mixed water reducer is more effective than single water reducer and results in reduction of water demand and porosity and improvement of mechanical strength.