The effect of water content， additives（polycarboxylic acid water reducer and quaternary ammonium surfactant） on the rheological properties of construction waste mud under different rest time were studied by fitting the rheological curve with Herschel-Bulkley model， and the action mechanism of additives was clarified. The results show that with the increase of water content， the rheological parameters of construction waste mud decrease. With the increase of the two additives content， the initial apparent viscosity and plastic viscosity of the construction waste mud first increase and then decrease. The yield stress of waste mud keeps increasing with increasing of the quaternary ammonium surfactant content， and first increase and then decrease with the increasing of the polycarboxylate superplasticizer content. The effect of polycarboxylate superplasticizer on the rheological properties of construction waste mud is better than that of quaternary ammonium surfactant under the same content. The dominant effect between the repulsive force of additive molecules and the adsorption force of the clay determines the rheological properties of construction waste mud.