Degree of consolidation of soil has a great influence on the strength of the soil. Direct shear apparatu with constant strain rate is applied to investigate direct shear strength change law with the increase of consolidation degree by saturated kaolin at all levels of consolidation pressure. Results show that direct shear strength increases linearly with the increase of degree of consolidation at all levels of consolidation pressure. Then,miniature vane shear apparatus is performed to study the micro vane strength changing rules. At the same time,considering the size effect,a small diameter consolidation apparatus cooperated with miniature vane shear apparatus is developed. Studies show that miniature vane shear strength grows linearly with the increase of consolidation degrees.Comparing the above two kinds of test results,it is found that they have good consistency. It confirms that miniature vane shear apparatus studying the shear strength change law of saturated soft clay is feasible.