Abstract: In the calculation of consolidation degree of sand drain ground, coefficient of consolidation is an important parameter. Normally we get the coefficient of consolidation by laboratory testing, but it is diffieult to prepare solid specimen for radial coefficient of consolidation. In the paper, the writer uses pore water pressure time curve on soft base treatment to calculate reckoning the consolidation degree of soft clay, analyzes by comparing with the laboratory test result, it summarizes their mutual relations and changes regularity. The result can be referenced for similar design.