Adopting 15MPa for pressure pre wetting, effect of different water absorption rate of fly ash ceramsite and shale ceramsite on the loss of slump and compressive strength of the plastic steel fiber lightweight aggregate concrete was studied under normal or 15MPa pressure for pre wetting. The results show that the water absorption of fly ash ceramsite is almost no difference under normal or 15MPa pressure, but the water absorption of shale ceramsite is greatly different if pre wetting is made under 15MPa pressure, the loss of slump is minimum for both concretes the compressive strength is relatively low in early stage of the plastic steel fiber lightweight aggregate concrete while the growth rate of compressive strength in late stage is higher. The way of pre wetting and water absorption rate of ceramsite have nothing to do with the middle or late compressive strength of the plastic steel fiber lightweight aggregate concrete. For compressive strength of lightweight aggregate concrete, the damage from 15MPa pressure on the lightweight aggregate can be neglected.