The experimental system of track mechanism-soil interaction is designed and constructed according to the new test system of soil bin developed by the Key Laboratory of Bionic Engineering in Ministry of Education, which is composed of soil trough and track-type trolley device as well as its supporting driving element and real-time test system through which can obtain parameters such as driving moment of the motor, horizontal displacement of trolley,sinkage in the traveling process of the trolley, inclined angle of the vehicle body, and motor speed, as well as the variation from the start to the smooth operation of the trolley device. Laser range finder is constructed with turnplate to realize the stage extraction of the track shape, which is not in contact with a road wheel. The vehicle load, track width and slip rate are taken as the experimental factors, the mechanism sinkage is taken as the experimental index, and orthogonal experiment design method is adopted. The experiments are carried out in three different Tightness degrees of the track, where sinkages and dipangles are obtained. The three regression equations of the sinkage on the vehicle body load, track width and slip rate are obtained by regression analysis, whose fitting effect is good, confidence is 0.99, and correlation coefficient is not less than 0.9. The average relative error between the test value and the calculated value of the regression equation is less than 10%. The results can be used to predict the stress distribution of flexible track and provide data support and important reference for the ground of soft soil.