There are many soft-clay sediment foundations in Yinchuan area, most of which are made of soft-clay silt from lakes. Its secondary consolidation deformation occupies a large proportion of its total deformation, and displays a greater volume of settlement after work completion, which seriously influence the normal use of buildings. The orthogonal experiments are designed to study the influence of factors such as current stress, dry density and OCR on the secondary consolidation behavior of soft-clay sediment of lake in Yinchuan. The regulation and mechanism of secondary consolidation is revealed. Some useful conclusions are reached to provide reference for projects design and construction.