This instrument is mainly used to determine the shear strength of the soil. Four soil samples are usually used. Under different vertical pressures (400Kpa, 300Kpa, 200Kpa, 100Kpa, 50Kpa optional), apply horizontal force to shear to obtain the shear stress at failure, and then determine the shear strength parameters and internal friction of the soil according to Coulomb's law Angle and cohesion. (Executive standard:T0140-1993/T0141-1993/T0142-1993/0143-1993/T0176-2007 in JTG E40-2007).