Abstract: The vegetation has been an important content in the ecologically protecting slope engineering.Therefore,researchers made many quantitative studies for the mechanical effect of reinforcing soil and steadying slope caused by plant roots.Now,there is a basic opinion among researchers as to this problem.It suggests that the action of plant roots reinforcing soil is mainly caused by vertical roots and lateral roots.Lateral roots can improve the soil layer’s whole tensile strength.Vertical roots can make the shallow soil layer anchored to the deep soil layer.These will increase the soil layer’s moving resistance,reinforce the soil layer,and restrain soil layer coast.The dynamic action principle of frictional the rootsoil bond deeply was studied.Based on the MohrCoulomb destroying theory,the destroying model of a rootsoil bond is formed under the utmost balance condition.The research of mechanical effect on root and soil at field presently is the influence of multiparameter on test and research.It is more difficult to be researched.The precision of study has been the influence of extent to a certain degree.A test system is designed to test data at real time in lab and field as well as the other supporting facilities of PCMCIA stick of A/D conversion block,and wellsuited device QT300 by DC power supply.According to various tests on the system,its capability can meet the need of test and analysis for machine effects on root and soil.The result between model calculation and experiment test is verified,and it shows that the model has a good precision and applicability.